QUARTER I Week 1 Subject: GENERAL MATHEMATICS Grade Level: 11 Date: ________________ Day: 2 (Lesson 2) Content Standard The learner demonstrates understanding of key concepts of functions. Performance Standard The learner is able to accurately construct mathematical models to represent real-life situations using functions. Learning Competency M11GM-Ia-2 The learner evaluates a function. I. OBJECTIVES Knowledge: Skills: Affective: II. CONTENT The learner: Finds the function value of f(x) at a specific value of x; Evaluates functions given a specific value of x; Shows accuracy in evaluating a function. Evaluating Functions III. LEARNING RESOURCES A. References 1. Teacher’s Guide Pages TG for SHS General Mathematics, pp. 11-13 2. Learner’s Materials Pages LM in General Mathematics, pp. 10-12 3. Textbook Pages General Mathematics by Orland Oronce Series 2016 4. Additional Materials Slide Decks on the Topic 5. Learning Resources (LR) portal B. Other Learning Resources Teacher’s Guide and Learner’s Material General Mathematics, Diwa Publishing, Senior High School Series. 2016 IV. PROCEDURES A. Reviewing or presenting the new lesson B. Establishing a purpose for the lesson Recall the definition of a function. C. Make a discussion about evaluating a function and say: Presenting examples of the new lesson Ask: What would happen if a sack of rice grains is poured into the opening of a working milling machine? If one thinks of functions as a function machine, evaluating a function is analogous to providing our machines with a valid input. ❖ Evaluating a function means replacing the variable in the function, in this case x, with a value 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). ❖ If one thinks of functions as a machine, evaluating a function is similar to providing our machines with a valid input. D. Discussing new concepts and practicing new skills #1 (See Example TG, p. 12). Take for example, a. evaluate at Step 1. Given Step 1. By substitution Step 2. Closure Property of Multiplication Step 3. Step 4. Thus, the function value is 4. E. Discussing new concepts and practicing new skills #2 Closure Property of Addition Ask: What is the function value of f as defined in Example 1 if evaluated at ? Below is the thorough discussion of the solution. Step 1. Given Step 2. by Substitution Step 3. Property Distributive Step 4. Property of Addition Step 5. Thus, the function value is Closure . F. Developing Mastery Let the learners work with a partner. Assign the problem below. The solution is provided for you. The teacher will have to mill around to facilitate the group activity. Call a representative to discuss the solution in the class. ( A classroom reward system could be used to further encourage and motivate the learners to participate in the activity, say the first five groups earns extra points.) Evaluate at . Solution: Step 1. Given Step 2. Substitution by Step 3. Squaring, DPMA Step 4. terms Combining similar Step 5. Thus, the function value is G. Finding practical applications of concepts and skills in daily living . Seatwork: 1. Mark started selling snacks in the nearby school. In one dayhe spends P200 for rent and P25 for each snack item he prepares. His expenses in a single day can be expressed as the function C(x) = 25x + 200, where x is the number of items and C(x) is his daily expenses in pesos. How much are his expenses if he prepares 100 snack items? 150 snack items? Answer: P2,700 and P3,950, respectively. 2. The function for the height of an object dropped from 100-meter tall platform at time t seconds is approximated by s(t) = -5( 𝑡�What is the height of the object after 2 seconds? after 4 seconds?2�+�100.�𝑇�ℎ𝑖�𝑠��𝑓�𝑜�𝑟�𝑚�𝑢�𝑙�𝑎��𝑖�𝑠��𝑏�𝑎�𝑠�𝑒�𝑑��𝑜�𝑛��𝑎�𝑛�� 𝑎�𝑝�𝑝�𝑟�𝑜�𝑥�𝑖�𝑚�𝑎�𝑡�𝑒�𝑑��𝑣�𝑎�𝑙�𝑢�𝑒�� Answer: 80 H. Making Generalizations and abstractions about the lesson I. Evaluating learning J. Additional Activities for application or remediation V. VI. and 20 meters, respectively. Ask: How is evaluating a function done? Evaluating a function can be done replacing the variable in the function, in this case x, with a value 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). See attachment. For remediation, assign learners to pick 2 problems that they did not worked on in the previous activity found in part I. Peer tutoring is desired for this purpose. For enrichment, assign Seatwork 5 on p. 11. The same rubric should be used for grading the learners’ outputs. REMARKS REFLECTION A. No. of learners who earned 80% in the evaluation B. No. of learners who require additional activities for remediation A. ____ No. of learners who earned 80% in the evaluation B. ____ No. of learners who require additional activities for remediation C. Did the remedial lessons work? No. of learners who have caught up the lesson C. Did the remedial lessons work? _____ No. of learners who have caught up the lesson. D. No. of learners who continue to require remediation D. ___ No. of learners who continue to require remediation E. Which of my teaching strategies worked well? Why did these work? Strategies used that work well: ___ Group collaboration ___ Games ___ Poweerpoint presentation Answering preliminary activities/exercises ___ Discussion ___ Differentiated Instruction ___ Case Method ___Role Playing /Drama ___ Think-Pair-Share (TPS) ___ Doscivery Method ___ Rereading of Paragraphs/Poems/Stories ___ Lecture Method Why? ___ Complete Ims ___ Availability of Materials ___ Pupil’s eagerness to learn ___ Group member’s cooperation in doing their tasks F. What difficulties did I encounter which my ___ Bullying among learners principal and supervisor help ___ Learner’s behavior/attitude Science/Computer/Internet Lab me solve? ___ Colorful Ims Works ___ Unavailable Technology G. What innovation or localized I used/discover which I wish to share with other teacher? ___ Equipment (AVR/LCD) ___ ___ Additional Clerical ___ Reading Readiness EVALUATION WORKSHEET No. ___ 1. Evaluate the following functions at x = 3. a) f(x) = x – 3 b. g(x) = 𝑥�3�−�3𝑥��+�5 d. p(x) =c. h(x) = 3𝑥�1𝑥�+3423+�𝑥��+�3�𝑥�− . For what values of x can we not evaluate the function f(x) = 𝑥�𝑥�2+−34�. 1 ANSWER KEY 2 . 3 . The domain of the function is given by {𝑥�:�𝑥�∈𝑅�,�𝑥�≠±2}