Name: Teacher: Period: Due Date: 10/28 (2.1A), 10/29 (2.1B), 10/30 (2.1C) WHAT IS A POLYNOMIAL? A polynomial can have: Constants Variables Whole Number Exponents A polynomial can’t have: Negative exponents Division by a variable Fractional exponents PRE CALCULUS HW 2.1 ABC TURNING POINTS OF A POLYNOMIAL FUNCTION A polynomial function f of degree n≥1 has at most n-1 turning point. A parabola has a degree of 2 and has at most 1 turning point. Examples of polynomials are 5, 3x, 4x2+5x-3 LEADING CO-EFFICIENT The leading co-efficient is the co-efficient of the variable with the greatest exponent. The leading co-efficient of 4x2+5x-3 is 4. The function below has a degree of 3 and has at most 2 turning points. DEGREE OF A POLYNOMIAL FUNCTION The degree of a polynomial function is equal to the greatest exponent. The degree of f(x)=4x2+5x-3 is 2. The parity of the degree is whether the degree is even or odd. END BEHAVIOR OF POLYNOMIAL FUNCTIONS For a polynomial function with a leading coefficient k, the chart below describes the end behavior (as x approaches either infinity) of functions with even or odd exponents. DISTINCT REAL ZEROES OF A POLYNOMIAL FUNCTION A polynomial function f of degree n≥1 has at most n distinct real zeroes. No picture. Distinct means different and you should know what zeroes are. Y-INTERCEPT OF A POLYNOMIAL FUNCTION Every polynomial function has 1 and only 1 y-intercept. MULTIPLICITY If there is a zero of a polynomial function that has an exponent like (x-c)m, then m is the multiplicity of the zero c. If m is even, the polynomial function is tangent to the x-axis at point c. If m is odd, the polynomial function crosses the x-axis at point c. Name: Teacher: Period: Due Date: 10/28 (2.1A), 10/29 (2.1B), 10/30 (2.1C) COMPLETE HW IN YOUR NOTEBOOK (WITH PLENTY OF ROOM TO EDIT) HW 2.1A Complete the following problems for Wednesday, Oct 28th 1. Describe the end behavior of 𝑓(𝑥) = −2𝑥 3 + 5𝑥 2 − 7𝑥 + 2 using limits and using the leading co-efficient and parity of degree. 2. State the number of distinct real zeroes and turning points of 𝑔(𝑥) = −6𝑥 7 + 25. 3. Determine the real zeroes of 𝑓(𝑥) = 𝑥 4 − 3𝑥 2 − 4 4. State the multiplicity of each zero of 𝑓(𝑥) = 6𝑥(𝑥 − 5)(𝑥 + 2)3 (𝑥 − 1)4 5. Sketch a function that is tangent to the x-axis at x = 5. 6. Sketch a function that crosses the x-axis at x = 5. 7. Describe everything you know that is different about two polynomial functions if one is described in #4 and the other is described in #5. 8. Based on the facts concerning what a polynomial can have and can’t have, what can’t possibly happen in a polynomial function? How would you describe a polynomial function? 1. 2. 3. 4. 5. 6. HW2.1B Determine the real zeroes of 𝑓(𝑥) = 𝑥 4 − 9𝑥 2 + 18 Determine the real zeroes of 𝑔(𝑥) = 𝑥 5 − 6𝑥 3 − 16𝑥 Describe the end behavior of 𝑔(𝑥) = 4𝑥 6 + 2𝑥 + 7 using limits and using the leading co-efficient and parity of degree. Determine the real zeroes and the multiplicity of each real zero of 𝑓(𝑥) = 3𝑥 5 − 18𝑥 4 + 27𝑥 3 Sketch 𝑔(𝑥) = 5(𝑥 − 1)(𝑥 + 2)3 (𝑥 + 6)2 Sketch 𝑓(𝑥) = 3𝑥 3 − 3𝑥 2 − 36𝑥 PRE CALCULUS HW 2.1 ABC HW2.1C For these functions: 1 1. 𝑓(𝑥) = 8𝑥 4 − 𝑥 2 + 𝑥 2. 𝑔(𝑥) = −5𝑥 7 + 6𝑥 4 + 8 3. ℎ(𝑥) = 3𝑥 6 + 4𝑥 3 − 3𝑥 − 8 4. 𝑚(𝑥) = 5𝑥 2 + 8𝑥 5 − 𝑥 −3 1 5. 𝑛(𝑥) = 5𝑥 4 + 𝑥 5 − 9 3 Answer the following questions (if a function is not a polynomial, you only answer question a): a. Is this a polynomial? Explain why or why not? b. What is the degree of the polynomial? c. What is the leading coefficient of the polynomial? d. What are the possible number of distinct real zeroes? e. Determine the end behavior using the leading co-efficient and parity of degree. 6. Determine the zeroes, state the multiplicity of each zero, and describe the behavior of the function at each zero. a. 𝑓(𝑥) = −(𝑥 + 2)2 (𝑥 − 4)2 b. 𝑓(𝑥) = −2𝑥 3 − 4𝑥 2 + 6𝑥 c. 𝑓(𝑥) = 𝑥 6 − 6𝑥 3 − 16