1. Section 6.1 An Introduction to Factoring Polynomials

2. 6.1 Lecture Guide: An Introduction to Factoring Polynomials Objective: Factor out the GCF of a polynomial.

3. Greatest Common Factor of a Polynomial: The GCF of a polynomial is the common factor that contains 1. the largest possible numerical coefficient and 2. the largest possible exponent on each variable factor.

4. Factor out the GCF of each polynomial. 1.

5. Factor out the GCF of each polynomial. 2.

6. Factor out the GCF of each polynomial. 3.

7. Factor out the GCF of each polynomial. 4.

8. 5. (a) Factor out the GCF of the polynomial (b) Use your calculator to complete the table below by letting equal the original polynomial andequal the factored form. –3 –2 –1 0 1 2 3

9. 5. (c) Graph (d) What would you conclude about the original polynomial and in the standard viewing window. How do the graphs compare? and the factored form?

10. Objective: Factor by Grouping.

11. Factoring a Four-Term Polynomial by Grouping Pairs of Terms Step 1. Be sure you have factored out the GCF if it is not 1. Step 2. Use grouping symbols to pair the terms so that each pair has a common factor other than 1. Example:

12. Factoring a Four-Term Polynomial by Grouping Pairs of Terms Step 3. Factor the GCF out of each pair of terms. Step 4. If there is a common binomial factor of these two groups, factor out this GCF. If there is no common binomial factor, try to use Step 2 again with a different pairing of terms. If all possible pairs fail to produce a common binomial factor, the polynomial will not factor by this method.

13. Factor each polynomial by the grouping method. 6.

14. Factor each polynomial by the grouping method. 7.

15. Factor each polynomial by the grouping method. 8.

16. Factor each polynomial by the grouping method. 9.

17. Objective: Use the zeros of a polynomial and the x-intercepts of the graph of to factor the polynomial. The relationship among the factors of a polynomial, the zeros of a polynomial function, and the x-intercepts of a graph of a polynomial function is an important one. Ifis an input value for which the output equals 0, then c is called a zero of the function.

18. Equivalent Statements about Linear Factors of a Polynomial Algebraically For a real constant c and a real polynomial, the following statements are equivalent. is a factor of Numerically, that is, is a zero of Graphically is an x-intercept of the graph of

19. 10. Consider the polynomial. Use the factored form ofto evaluate each expression. (a) (b) (c) (d)

20. 11. Use the table and graph provided for to answer each question. (a) List the factors of. (b) List the zeros of. (c) List the x-intercepts of the graph.

21. 12. Consider the polynomial (a) List the zeros of. (b) List the x-intercepts of the graph. (c) Use parts (a) and (b) to determine the factored form of the polynomial

22. Use the factored form of each polynomial to list the zeros and the x-intercepts of the graph of 13. Zeros: x-intercepts:

23. Use the factored form of each polynomial to list the zeros and the x-intercepts of the graph of 14. Zeros: x-intercepts:

24. Polynomial: Factored Form: Zeros: x-intercepts: 15. Complete the following table for each polynomial.

25. Polynomial: Factored Form: Zeros: x-intercepts: 8 and 10 16. Complete the following table for each polynomial.

26. Polynomial: Factored Form: Zeros: x-intercepts: 17. Complete the following table for each polynomial.

27. 18. Complete the following table for each polynomial. Polynomial: Factored Form: Zeros: x-intercepts:

28. Use the given table and graph to factor each polynomial. 19. by

29. Use the given table and graph to factor each polynomial. 20. by

30. 21. Use a graphing calculator to create a table and a graph for and determine the zeros. Then use the zeros to factor the polynomial. Zeros: Factored form:

31. 22. Use a graphing calculator to create a table and a graph for and determine the zeros. Then use the zeros to factor the polynomial. Zeros: Factored form:

32. Use a graphing calculator to graph and calculate the zeros. Then use the zeros to factor the polynomial. See Calculator Perspective 6.1.1. 23.

33. Use a graphing calculator to graph and calculate the zeros. Then use the zeros to factor the polynomial. See Calculator Perspective 6.1.1. 24.

34. Factoring a Polynomial with Two Variables Use the factored form of a polynomial in one variable to factor each polynomial in two variables. 25. Given: Factor: 26. Given: Factor: