Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR LEARNER ACTIVITY SHEET/WORKSHEETS in GENERAL MATHEMATICS Name of Learner: __________________________ Date: _____________ Grade Level: _________ Teacher_________________________ Section:________ FUNCTIONS Title I. Introduction In Mathematics, a function is a relation between a set of inputs and set permissible outputs. Function has the property that each input is related to exactly one output. We can relate functions to a vending Machine. You “input” money and your “output” is a candy or chips II. MELC with code Represents real-life situations using functions, including piece-wise functions. M11GM-Ia-1 III. Strategy A. Explore EXAMPLE: “Multiply by 2” is a very simple function. Answer and complete the table below Input Relationship Output 0 x2 0 2 x2 4 7 x2 10 x2 12 x2 Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department 24 Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR 50 x2 B. Learn The previous activity helps us understand/grasp what FUNCTION means. Function A Function is a relation where each element in the domain is related to only one value in the range by some rule A Function is a set of ordered pairs (x,y) such that no two ordered pairs have the same x-value but different y-values. Using function functional notation, we can write f(x)=y, read as “f of x is equal to y”. In Particular, if (1,2) is an ordered pair associated with the function f, then we say that f(2)=1 EXAMPLE 1. Which of the following relations are functions? f = { (1,2), (2,3), (3,5), (4,7)} g = { (1,3), (1,4), (2,5), (2,6), (3,7)} h = { (1,3), (2,6), (3,9), (n, 3n),…} Solution: The relation f and h are functions because no two ordered pairs have the same x-value but different y-values. Meanwhile, g is not a function because (1, 3) and (1, 4) are ordered pairs with the same x-value but different y-values. Relations and Functions can be represented by mapping diagrams where the elements of the domain are mapped to the range using arrows. In this case, the relation or function is represented by the set of all the connections represented by by the arrows. VERTICAL LINE TEST- A graph represents a function if and only if each vertical line intersects the graph at most once. Function Not Function Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR PIECEWISE FUNCTIONS Some situations can only be described by more than one formula, depending on the value of the independent variable. EXAMPLE 1. A user is charged P300.00 monthly for a particular mobile plan, which includes 100 free text messages. Messages in excess of 100 are charged P1 each. Represent the monthly cost for text messaging using the function t(m), where m is the number messages sent in a month. SOLUTION: The cost of text messaging can be expressed by the piecewise t (m) = { 300 300 + 𝑚 , 𝑖𝑓 0 < 𝑚 ≤ 100 , 𝑚 > 100 2. A jeepney ride costs P8.00 for the first kilometers, and each additional integer kilometer adds P1.50 to the fare. Use a piecewise function to represent the jeepney’s fare in terms of the distance (d) in kilometers. SOLUTION: The input value is distance and the output is the cost of the jeepney fare. If F(d) represents the fare as a function of the distance, the function can be represented as follows: F (d) = { 8.00 (8 + 1.5⌊𝑑⌋ ) , 𝑖𝑓 0 < 𝑑 ≤ 4 , 𝑖𝑓 𝑑 > 4 C. Engage Direction: Apply the Piecewise Function to answer the problem below. 1. A computer shop charges P20.00 per hour (or a fraction of an hour) for the first two hours and an additional P10.00 per hour for each succeeding hour. Represent your computer’s rental fee using the function R(t) where t is the number of hours you spent on the computer SOLUTION: Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR D. Apply A. Direction: Write F if the relation is a function and write NF if it is not. 1._________ 2._________ 3._________ 4._________ g= {(1,3),(1,4),(2,5),(2,6),(3,7)} h= {(1,5),(2,4),(1,5),(2,5),(3,7)} y= {(1,2),(2,3),(3,5),(4,7),(5,8)} p= {(1,0),(2,4),(5,5),(7,6),(8,7)} 4 10 5._________ p= {(2,3),(2,4),(5,5),( 2 ,6),(8,7)} 6._________ p= {(0,0),(1,0),(0,4),(5,6),(0,7)} B. Use the piecewise function to answer the problem below A student from WNHS-SHS charged P200.00 monthly for a mobile internet plan. Included in his promo is the 50 free text messages to all network. Messages in excess of P50.00 are charged P1.00 each. Represent the monthly cost for text messaging using the function t(m), where m is the number of messages sent in a month. SOLUTION: Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR IV. Guide Questions DIRECTION; Write F if the graph is a function and NF if it is not 7._______ 8._______ 9. ________ V. Rubrics VI. References: GENERAL MATHEMATICS learner’s Material VII. Key to Correct Answers Prepared by TEODORO G. ABAN Subject Teacher Noted: MIGUEL P. DABUET Secondary School Principal IV Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department 10. _________ Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR LEARNER ACTIVITY SHEET/WORKSHEETS in GENERAL MATHEMATICS Name of Learner: __________________________ Date: _____________ Grade Level: _________ Teacher_________________________ Section:________ EVALUATING FUNCTIONS Title I. Introduction In our introduction to functions lesson, we related functions to a vending machine. You input money and your output is candy or chips. We’re going to go back to that visual as we begin evaluating functions. We are going to “input” a number and our “output” is the answer. II. MELC with code Evaluates a function. M11GM-Ia-2 III. Strategy A. Explore EXAMPLE: Evaluate the following function functions at x=1.5 1. f (x) = 2x + 1 2. q (x) = 𝑥 2 -2x + 2 3. g (x) = √𝑥 + 1 4. r (x)= 2𝑥+1 𝑥−1 5. F(x) = ⌊𝑥⌋ + 1, where ⌊𝑥⌋ is the greatest integer function. B. Learn The previous activity guides and anchored us on how to evaluate a particular function. Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR Evaluating a Function Evaluating a function means replacing the variable in the function, in this case x, with a value of from the function’s domain and computing for the result. To denote that we are evaluating f at a for some a in the domain of f, we write f(a) EXAMPLE 1.Evaluate the functions q (x) = 𝑥 2 - 2x + 2 at x=3 Solution: q (x) = 𝑥 2 - 2x + 2 substitute/plug-in the value of x to the equation q (x) = (3)2 – 2(3) + 2 simply q (x) = 9 -6 + 2 simplify further (using MDAS) q (x) = 5 final answer. 2. Evaluate the function t (x) = 2𝑥+1 𝑥−1 at x= (a + 1) Solution: t(x)= 2𝑥+1 t(x)= 2(𝑎+1)+1 t(x)= 2𝑎+2+1 t(x)= 2𝑎+3 substitute/plug-in the value of x to the equation. 𝑥−1 simplify 2(a + 1) using distributive property (𝑎+1)−1 simplify further by combining like terms 𝑎+1−1 Final answer 𝑎 3. Evaluate the function g(x) = 𝑥 2 + 2x +1 at x = b -1 Solution: g(x) = 𝑥 2 + 2x +1 substitute/plug-in the value of x to the equation. g(x) = (𝑏 − 1)2 + 2(b – 1) +1 simplify (𝑏 − 1)2 using foil method while 2(b – 1) using distributive property g(x) =( 𝑏 2 – 2b + 1)+ 2b – 2 +1 combine like terms g(x) = 𝑏 2 final answer Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR C. Engage For what values of x can we not evaluate the function f(x) = SOLUTION: D. Apply A. Evaluate the following functions at x = 3 1. f(x) = x - 3 2. g(x) = 𝑥 2 – 3x + 5 3 3. h(x) = √𝑥 2 + 𝑥 3 4. p(x) = 𝑥 2 +1 𝑥−4 5. f(x) = |𝑥 − 5| where |𝑥 − 5| means the absolute value of x – 5. B. Evaluate the function f(x) = 4𝑥 2 – 3x when f(a + b) SOLUTION: Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department 𝑥+3 𝑥 2 −4 Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR IV. Guide Questions DIRECTION: Evaluate the following functions at x = -4 1. f(x) = 𝑥 3 – 64 2. g(x) = |𝑥 3 − 3𝑥 2 − 1| 3. r(x) = √5 − 𝑥 V. Rubrics VI. References: GENERAL MATHEMATICS learner’s Material VII. Key to Correct Answers Prepared by TEODORO G. ABAN Subject Teacher Noted: MIGUEL P. DABUET Secondary School Principal IV Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR LEARNER ACTIVITY SHEET/WORKSHEETS in GENERAL MATHEMATICS Name of Learner: __________________________ Date: _____________ Grade Level: _________ Teacher_________________________ Section:________ OPERATIONS ON FUNCTIONS Title I. Introduction Functions with overlapping domains can be added, subtracted, multiplied, and be divided. If f(x) and g(x) are two functions, then for all x in the domain of both functions the sum, difference, product and quotient are define as follows (f + g) (x) = f(x) + g(x) (f – g) (x) = f(x) – g(x) (f * g) (x) = f(x) * g(x) (f / g) (x) = f(x)/g(x) II. MELC with code Performs addition, subtraction, multiplication, division, and compositions of functions.M11GM-Ia-3 III. Strategy A. Explore EXAMPLE: and 2 5 2. Find the difference of 3 6 1.Find the sum of 1 2 and 2 6 3. Find the product of (x-1) and (x + 1) Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR B. Learn Operations on functions ( sum, difference, product, and quotient) 1 𝑥−3 Find the sum of 2 𝑥−5 and Solution: 1. 1 𝑥−3 + 2 𝑥−5 = = = = 𝑥−5 (𝑥−3)(𝑥−5) + 2(𝑥−3) (𝑥−3)(𝑥−5) 𝑥−5+ 2(𝑥−3) (𝑥−3)(𝑥−5) 𝑥−5+ 2𝑥−6 (𝑥−3)(𝑥−5) 𝑥−11 𝑥 2 −8𝑥+15 2. Find the Product of Ans. 𝑥 2 −4𝑥−5 𝑥 2 −3𝑥+2 and 𝑥 2 −5𝑥−6 𝑥 2 −3𝑥−10 Solution: 𝑥 2 −4𝑥−5 𝑥 2 −3𝑥+2 = (𝑥+1)(𝑥−5) = (𝑥+1)(𝑥−3) = (𝑥−2)(𝑥−1) 𝑥 2 −5𝑥−6 𝑥 2 −3𝑥−10 (𝑥−2)(𝑥−3) (𝑥−5)(𝑥+2) (𝑥−1)(𝑥+2) 𝑥 2 −2𝑥−3 𝑥 2 + 𝑥−2 Ans. 2. Find the quotient of 2𝑥 2 +𝑥−6 2𝑥 2 +7𝑥+5 and 𝑥 2 −2𝑥−8 2𝑥 2 −3𝑥−20 Solution: Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR = = = = 2𝑥 2 +𝑥−6 ÷ 2𝑥 2 +7𝑥+5 2𝑥 2 +𝑥−6 2𝑥 2 +7𝑥+5 (2𝑥−3)(𝑥+2) (2𝑥+5)(𝑥+1) 2𝑥−3 𝑥+1 𝑥 2 −2𝑥−8 Get the reciprocal of 2𝑥 2 −3𝑥−20 𝑥 2 −2𝑥−8 𝑥 2 −3𝑥−20 2𝑥2 −3𝑥−20 𝑥2 −2𝑥−8 (𝑥−4)(2𝑥+5) (𝑥+2)(𝑥−4) Ans. C. Engage Find the Product 𝑥 2 +4𝑥−21 𝑥 2 −16 ( 𝑥 2 −6𝑥+9 ) (𝑥 2 +3𝑥−28 ) SOLUTION: D. Apply Consider the following functions below: g(x)=2x-4 f(x)=x+6 𝑥+5 h(x)= 𝑥+7 Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department 𝑥−3 t(x)= 𝑥+4 Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR Determine the following function. 1. (g + f)(x) 2. (h - f)(x) 3. (t h)(x) 4. (g f)(x) 5. (f + t)(x) IV. Guide Questions 𝑥 2 −1 Find the quotient of ( 𝑥 2 +4𝑥+4 ) and ( 𝑥 2 +8𝑥+7 2𝑥+4 ) V. Rubrics VI. References: GENERAL MATHEMATICS learner’s Material VII. Key to Correct Answers Prepared by TEODORO G. ABAN Subject Teacher Noted: MIGUEL P. DABUET Secondary School Principal IV Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR LEARNER ACTIVITY SHEET/WORKSHEETS in GENERAL MATHEMATICS Name of Learner: __________________________ Date: _____________ Grade Level: _________ Teacher_________________________ Section:________ COMPOSITION ON FUNCTIONS Title I. Introduction In our introduction to functions lesson, we related functions to a vending machine. You input money and your output is candy or chips. We’re going to go back to that visual as we begin evaluating functions. We are going to “input” a number and our “output” is the answer. II. MELC with code Evaluates a function. M11GM-Ia-2 III. Strategy A. Explore EXAMPLE: Evaluate the following function functions at x=1.5 1. f (x) = 2x + 1 2. q (x) = 𝑥 2 -2x + 2 3. g (x) = √𝑥 + 1 4. r (x)= 2𝑥+1 𝑥−1 5. F(x) = ⌊𝑥⌋ + 1, where ⌊𝑥⌋ is the greatest integer function. B. Learn The previous activity guides and anchored us on how to evaluate a particular function. Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR Evaluating a Function Evaluating a function means replacing the variable in the function, in this case x, with a value of from the function’s domain and computing for the result. To denote that we are evaluating f at a for some a in the domain of f, we write f(a) EXAMPLE 1.Evaluate the functions q (x) = 𝑥 2 - 2x + 2 at x=3 Solution: q (x) = 𝑥 2 - 2x + 2 substitute/plug-in the value of x to the equation q (x) = (3)2 – 2(3) + 2 simply q (x) = 9 -6 + 2 simplify further (using MDAS) q (x) = 5 final answer. 2. Evaluate the function t (x)= 2𝑥+1 𝑥−1 at x= (a + 1) Solution: t(x)= 2𝑥+1 t(x)= 2(𝑎+1)+1 t(x)= 2𝑎+2+1 t(x)= 2𝑎+3 substitute/plug-in the value of x to the equation. 𝑥−1 simplify 2(a + 1) using distributive property (𝑎+1)−1 simplify further 𝑎+1−1 Final answer 𝑎 3. Evaluate the function g(x) = 𝑥 2 + 2x +1 at x = b -1 Solution: g(x) = 𝑥 2 + 2x +1 substitute/plug-in the value of x to the equation. g(x) = (𝑏 − 1)2 + 2(b – 1) +1 simplify (𝑏 − 1)2 using foil method while 2(b – 1) using distributive property g(x) =( 𝑏 2 – 2b + 1)+ 2b – 2 +1 combine like terms g(x) = 𝑏 2 final answer Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR C. Engage For what values of x can we not evaluate the function f(x) = SOLUTION: D. Apply A. Evaluate the following functions at x = 3 1. f(x) = x - 3 2. g(x) = 𝑥 2 – 3x + 5 3 3. h(x) = √𝑥 2 + 𝑥 3 4. p(x) = 𝑥 2 +1 𝑥−4 5. f(x) = |𝑥 − 5| where |𝑥 − 5| means the absolute value of x – 5. B. Evaluate the function f(x) = 4𝑥 2 – 3x when f(a + b) SOLUTION: Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department 𝑥+3 𝑥 2 −4 Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR IV. Guide Questions DIRECTION: Evaluate the following functions at x = -4 1. f(x) = 𝑥 3 – 64 2. g(x) = |𝑥 3 − 3𝑥 2 − 1| 3. r(x) = √5 − 𝑥 V. Rubrics VI. References: GENERAL MATHEMATICS learner’s Material VII. Key to Correct Answers Prepared by TEODORO G. ABAN Subject Teacher Noted: MIGUEL P. DABUET Secondary School Principal IV Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR LEARNER ACTIVITY SHEET/WORKSHEETS in GENERAL MATHEMATICS Name of Learner: __________________________ Date: _____________ Grade Level: _________ Teacher_________________________ Section:________ OPERATIONS ON FUNCTIONS Title I. Introduction Let f and g be functions. The Composite Function denoted by (f ◦ g) is defined by (f ◦ g)(x) = f(g(x)). The process of obtaining a composite function is called function Composition. II. MELC with code Solve problems involving functions. M11GM-Ia-4 III. Strategy A. Explore Use the following functions below: f (x) =2x + 1 g (x) = 𝑥 2 – 1 Find and simplify (g◦ f)(x) Solution: (g◦ f)(x) = g(f(x)) = 𝑥 2 -1 = (𝑓(𝑥))2 – 1 = ( 2𝑥 + 1)2 – 1 = 4𝑥 2 + 4x + 1 – 1 = 4𝑥 2 + 4x (g◦ f)(x) = g(f(x)) = 4x (x + 1) Ans. Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR B. Learn Composition of Functions Use the following functions below f (x) = 2x + 1 g(x) = √𝑥 + 1 q (x) = 𝑥 2 – 2x + 2 p(x) = F(x) = ⌊𝑥⌋ + 1 1. Find and simplify (g◦ f)(x) Solution: (g◦ f)(x) = g(f(x)) = √𝑥 + 1 = √𝑓(𝑥) + 1 = √(2𝑥 + 1) + 1 (g◦ f)(x) = g(f(x)) = √2𝑥 + 2 Ans. 2. Find and simplify (q◦ f)(x) Solution: (q◦ f)(x) = q(f(x)) = 𝑥 2 – 2x + 2 = (𝑓(𝑥))2 – 2(f(x)) + 2 = (2𝑥 + 1)2 – 2(2x + 1) + 2 = 4𝑥 2 + 4x + 1 - 4x -2 + 2 (q◦ f)(x) = q(f(x)) = 4𝑥 2 + 1 Ans. 3. Find and simplify (f◦ p)(x) Solution: (f◦ p)(x) = f(p(x)) = 2x + 1 = 2p(x) + 1 = 2[ = [ = (f◦ p)(x) = f(p(x)) = 2𝑥+1 𝑥−1 ]+1 4𝑥+2 𝑥−1 ]+1 (4𝑥+2)+(𝑥−1) 𝑥−1 5𝑥+1 𝑥−1 Ans. Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department 2𝑥+1 𝑥−1 Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR C. Engage Let f (x) = 3𝑥 2 – 2x – 1 Solve and simplify and h (x) = 𝑥 2 – 1. (f◦ h)(x) SOLUTION: D. Apply Let t (x) = 𝑥+1 and 𝑥−1 k (x) = 𝑥 2 – 1. Solve and simplify (k◦ t)(x) Solution: IV. Guide Questions Let f(x) = 2x – 15 Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR Determine f(f(f(f(15)))) V. Rubrics VI. References: GENERAL MATHEMATICS learner’s Material VII. Key to Correct Answers Prepared by TEODORO G. ABAN Subject Teacher Noted: MIGUEL P. DABUET Secondary School Principal IV Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR LEARNER ACTIVITY SHEET/WORKSHEETS in GENERAL MATHEMATICS Name of Learner: __________________________ Date: _____________ Grade Level: _________ Teacher_________________________ Section:________ REPRESENTING REAL-LIFE SITUATIONS USING RATIONAL FUNCTIONS Title I. Introduction A polynomial function p of degree n is a function that can be written in the form p (x) = 𝑎𝑛 𝑥 𝑛 + 𝑎𝑛−1 𝑥 𝑛−1 + 𝑎𝑛−2 𝑥 𝑛−2 + …+ 𝑎1 𝑥 𝑛 + 𝑎0 where 𝑎0 , 𝑎1 ,…, 𝑎𝑛 ϵ IR, 𝑎𝑛 ≠ 0, and n is a positive integer. Each addend of the sum is a term of the polynomial function. The constant 𝑎0 , 𝑎1 , 𝑎2 ,…𝑎𝑛 are the coefficients. The leading coefficient is 𝑎𝑛 . The leading term is 𝑎𝑛 𝑥 𝑛 , and the constant term is 𝑎0 . II. MELC with code Represents real-life situations using rational functions. M11GM-Ib-1 III. Strategy A. Explore An object is to travel a distance of 10 meters. Express velocity v as a function of travel time t, in seconds The following table of values show v for various of t. t (seconds) v (meter per second 1 2 3 4 5 10 5 2.5 2 1 Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR The function v (t) = 10 𝑡 can represent v as a function of t. B. Learn A Rational Function is a function of the form f(x) = 𝑝(𝑥) 𝑞(𝑥) where p(x) and q(x) are polynomial functions and q(x) is not zero function (i.e., q(x) ≡ 0). The domain of f(x) is the set of all values of x where q(x) ≠ 0. EXAMPLE 5𝑡 (in mg/mL) represents the concentration of a drug in a patient’s bloodstream t hours after the drug was administered. Construct a table of values for c(t) for t = 1, 2, 5, 10. Round off answers to three decimal places. Use the to sketch a graph and interpret the results. Suppose that c(t) = 𝑡 2 +1 Solution: a. c(0) = 5𝑡 𝑡 2 +1 b. c(1) = c. c(2) = d. c(5) = = 5(1) (1)2 +1 5(2) (2)2 +1 5(5) (5)2 +1 e. c(10) = 5(0) (0)2 +1 = 2.5 =2 = 0.962 5(10) (10)2 +1 t C(t) =0 = 0.495 0 0 1 2.5 2 2 Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department 5 0.962 10 0.495 Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR C. Engage In an organ pipe, the frequency f of vibration of air is inversely proportional to the length L of the pipe. Suppose that the frequency of vibration in a 10-foot pipe is 54 vibrations per second. Express f as a function of L. Solution: Since f is inversely proportional to L, then f = proportionality. If L= 10 then f=54. Thus, 54 = as a function of L. 𝑘 , 10 𝑘 𝐿 , where k is the constant of k= 540. Thus, the function f(L)= D. Apply Given the polynomial function p(x) = 12 + 4x - 3𝑥 2 - 𝑥 3 . 1. The degree of the polynomial Ans. 2. The leading coefficient Ans. 3. The constant term Ans. 4. The number of zeroes Ans. IV. Guide Questions Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department 540 𝐿 represents f Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR V. Rubrics VI. References: GENERAL MATHEMATICS learner’s Material VII. Key to Correct Answers Prepared by TEODORO G. ABAN Subject Teacher Noted: MIGUEL P. DABUET Secondary School Principal IV Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR LEARNER ACTIVITY SHEET/WORKSHEETS in GENERAL MATHEMATICS Name of Learner: __________________________ Date: _____________ Grade Level: _________ Teacher_________________________ Section:________ RATIONAL FUNCTIONS, EQUATIONS, AND INEQUALITIES Title I. Introduction A Rational Expression is an expression that can be written as a ratio of two polynomials. Some examples of rational expressions are 𝑥 2 , 𝑥 2 +2𝑥+3 5 , 𝑥−3 𝑥+1 II. MELC with code Distinguishes rational function, rational equation, and rational inequality. M11GMIb-2 III. Strategy A. Explore Every polynomial function is a rational function ex. q(x) = 1 A function that cannot be written in the form polynomial, ex f(x)=sin(x) A constant function such as f(x)= 𝜋 B. Learn A Rational Function is a function of the form f(x) = 𝑝(𝑥) 𝑞(𝑥) where p(x) and q(x) are polynomial functions and q(x) is not zero function (i.e., q(x) ≡ 0). The domain of f(x) is the set of all values of x where q(x) ≠ 0. Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR EXAMPLE The definitions of rational equations, inequalities, and functions are shown below Rational equation Rational Inequality Rational Function Definition An equation An inequality A function of the 𝑝(𝑥) involving rational involving rational form f(x) = 𝑞(𝑥) expression expressions. where p(x) and q(x) are polynomial functions and q(x) is not zero function (i.e., q(x) ≡ 0). 2 3 1 5 2 𝑥 2 +2𝑥+3 Example =5 < f (x) = x 2𝑥 x−4 𝑥 𝑥+1 C. Engage Determine whether the given is a rational function, rational equation, a rational inequality or none of these. Explain your answer. 𝑥+ 3 𝑥−5 >√4𝑥 + 7 Ans.___________________________________________ D. Apply Determine whether the given is a rational function, rational equation, a rational inequality or none of these. 1. 8 = 𝑥+2 𝑥−1 2. x >√𝑥 + 2 3. 2x ≥ 7 𝑥+4 ___________________ ___________________ ____________________ Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR 4. f (x) = 5. 𝑥 2 = 𝑥+ 3 𝑥2 −5 – 6 ____________________ 4 𝑥+9𝑥3 ____________________ IV. Guide Questions V. Rubrics VI. References: GENERAL MATHEMATICS learner’s Material VII. Key to Correct Answers Prepared by TEODORO G. ABAN Subject Teacher Noted: MIGUEL P. DABUET Secondary School Principal IV Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR LEARNER ACTIVITY SHEET/WORKSHEETS in GENERAL MATHEMATICS Name of Learner: __________________________ Date: _____________ Grade Level: _________ Teacher_________________________ Section:________ SOLVING RATIONAL EQUATIONS AND INEQUALITIES Title I. Introduction A rational equation or inequality can be solved for all x values that satisfy the equation or inequality. This lesson will help students recall and use their knowledge on finding the LCD, simplifying complex rational expressions and equations a inequality symbols. II. MELC with code Solves rational equations and inequalities. M11GM-Ib-3 III. Strategy A. Explore Recall your knowledge on Least Common Denominator, Factorization, simplest form and answer the problem below. You may solve the unknown variable. 1. 2 5 2. 3 10 + 3 15 = 3. 𝑥 2 −1 𝑥+1 =5 + x -2 = 2x -3 B. Learn To solve a rational equation 1. Eliminate denominators by multiplying each term of the equation by the least common denominator. 2. Note that eliminating denominators may introduce extraneous solutions. Check the solutions of the transformed equations with the original equation. Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR EXAMPLE 1 Solve for x : 2 𝑥 - 3 2x = 1 5 Solution: The LCD of all the denominators is 10x. Multiply both sides of the equation by 10x and solve the resolving equation. 2 3 1 10x (𝑥) – 10x(2𝑥) = 10x (5) 20 – 15 = 2x 5 = 2x 5 2 = x or x= 5 2 Ans. EXAMPLE 2 Solve for x : 𝑥 𝑥+2 - 1 𝑥−2 = 8 𝑥 2 −4 Solution: Factor each denominator in the rational expression. 𝑥 𝑥+2 - 1 𝑥−2 = 8 (𝑥+2)(𝑥−2) Multiply the LCD both sides of the equation to remove the denominators. 𝑥 1 8 (x + 2)(x – 2) (𝑥+2) (𝑥−2) = (x + 2)(x – 2)((𝑥+2)(𝑥−2)) x(x – 2) – (x + 2) = 8 𝑥 2 – 3x – 10 = 0 Upon reaching this this step, we can use strategies for solving polynomial equations. 𝑥 2 – 3x – 10 = 0 (x + 2)(x – 5) = 0 x+2=0 x–5=0 x = -2 x=5 since x = -2 makes the original equation undefined, x = 5 is the only answer. Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR To solve rational inequalities a. rewrite the inequality as a single rational expression on one side of inequality symbol and 0 on the other side. b. determine over what intervals the rational expression takes on positive and negative values. i. locate the x values for which the rational expression is zero or undefined(factoring the numerator and denominator is a useful strategy). ii. Mark the numbers found in (i) on a number line. Use a shaded circle to indicate that the value is included in the solution set, and a hollow circle to indicate that the value is excluded. These numbers partition the number line into intervals. iii. Select a test point within the interior of each interval in (ii). The sign of the rational expression at this test point is also the sign of the rational expression at each interior point in the aforementioned interval. vi. Summarize the intervals containing the solutions. EXAMPLE Solve the inequality 2𝑥 𝑥+1 ≥0 Solution: a. Rewrite the inequality as a single rational expression. 2𝑥 𝑥+1 –1≥0 2𝑥−(𝑥+1) 𝑥+1 𝑥−1 𝑥+1 ≥0 ≥0 b. The rational expression will be zero at x = 1 and undefined for x = -1. The value of x = 1 is included while x = -1 is not. Mark these on the number line. Use a shaded circle for x = 1 ( a solution) and an unshaded circle for x = -1 (not included). Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR c. Choose convenient test points in the intervals determined by -1 and 1 to 𝑥−1 determine the sign of 𝑥+2 in these intervals. Construct a table of signs as shown below. Interval x<1 -1<x<1 x>1 Test Point x = -2 x=0 x=2 x–1 – – + x+1 – – + 𝑥−1 𝑥+1 + – + d. Since we are looking for the intervals where the rational expression is positive or zero, we determine the solution to be the set {𝑥 𝜖𝑅|𝑥 < −1 𝑜𝑟 𝑥 ≥ 1}. Plot this on the number line. C. Engage Solve x : 𝑥2 𝑥−3 = 𝑥+2 2𝑥−5 Solution: Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR D. Apply 1. Solve the inequality 2. Solve the inequality 3 𝑥−2 5𝑥 𝑥−1 ≥ 1 𝑥 <4 IV. Guide Questions Solve for x : 𝑥+6 𝑥−4 ≥ 1 𝑥+1 V. Rubrics VI. References: GENERAL MATHEMATICS learner’s Material(pg. VII. Key to Correct Answers Prepared by TEODORO G. ABAN Subject Teacher Noted: MIGUEL P. DABUET Secondary School Principal IV Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR LEARNER ACTIVITY SHEET/WORKSHEETS in GENERAL MATHEMATICS Name of Learner: __________________________ Date: _____________ Grade Level: _________ Teacher_________________________ Section:________ REPRESENTATION OF RATIONAL FUNCTIONS Title I. Introduction A Rational Function is a function of the form f(x) = 𝑝(𝑥) 𝑞(𝑥) where p(x) and q(x) are polynomial functions and q(x) is not zero function (i.e., q(x) ≡ 0). The domain of f(x) is the set of all values of x where q(x) ≠ 0. Average speed (or velocity) can be computed by the formula s = d/t. consider a 100-meter track used for foot races. The speed of a runner can be computed by 100 taking time for him to run track and applying it to the formula s = , since the 𝑡 distance is fixed at 100 meters. II. MELC with code Represents a rational function through its: (a) table of values, (b) graph, and (c) equation. M11GM-Ib-4 III. Strategy A. Explore Consider the example below: Represent the speed of a runner as a function of the time it takes to run 100 meters Solution: Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR Since the speed of a runner depends on the time it takes to run 100 meters, we can represent speed as a function of time. Let x represent the time it takes to run 100 meters. Then the speed can be represented as a function s(x) as follows: s (x) = 100 𝑥 Observe that it is similar to the structure to the formula s = distance, and time. 𝑑 𝑡 relating speed, B. Learn To further explain the lesson, do consider the second example below Continuing the scenario above, construct a table of values for speed of runner against different run times. Solution: A table of values can help us determine the behaviour of a function as the variable x changes. The current word record ( as of October 2015) for the 100-meter dash run is 9.58 seconds set by the Jamaican Usain Bolt in 2009. We start our table of values at 10 seconds. Let x be the runtime and s(x) be the speed of the runner in meters per second, 100 where s(x) = 𝑥 . The table of values for run times from 10 seconds to 20 seconds is as follows: x 10 12 14 16 18 20 s (x) 10 8.33 7.14 6.25 5.56 5 From the table above we can observe that the speed decreases with time. We can use a graph to determine if the points on the function follow a smooth curve or a straight line. Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR C. Engage Plot the points on the table of values on a Cartesian plane. Determine if the points 100 on the function s(x) = follow a smooth curve or a straight line. 𝑥 Solution: D. Apply 𝑥−1 1. Represent the rational function given by f(x) = 𝑥+1 using a table of values and plot a graph of the function by connecting points. Solution: IV. Guide Questions 𝑥 2 −3𝑥−10 Represent the rational function given by f(x) = using a table of values 𝑥 and plot a graph of the function by connecting points. V. Rubrics Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department Republic of the Philippines Department of Education REGION VIII DIVISION OF SAMAR DISTRICT OF WRIGHT I WRIGHT NATIONAL HIGH SCHOOL SENIOR HIGH SCHOOL DEPARTMENT PARANAS, SAMAR VI. References: GENERAL MATHEMATICS learner’s Material(pg. VII. Key to Correct Answers Prepared by TEODORO G. ABAN Subject Teacher Noted: MIGUEL P. DABUET Secondary School Principal IV Call or text. For updates. Visit. 0917-304-5347 / 0949-994-2133 Wright NHS Senior High Department