The homework for 6th and 7th period was a "More on Compositions" worksheet and the answers are as follows:
1. (8x + 5)/(4x + 3) 2. 16x2 + 16x + 3 3. 2x+2 + 7 4. (2x2 - 4x - 1)/(x2 - 2x) 5. (-2x + 1)/x2 6. 22x - 1 7. x4 - 4x3 + 2x2 + 4x 8. (3x - 2)/(2x - 1)
Back page: 1. a) {1, 2, 3, 4} b) {1, 2, 3, 5} 2. a) {0, 1, 2, 4} b) {1, 3, 4, 5} 3. {(0, 1), (1, 2), (2, 3)} Although g maps 4 to 5, 5 is not in the domain of f. 4. {0, 1, 2} is a subset of the domain of g(x) because g provides the initial x values for f(g(x)). The range is {1, 2, 3} which is a subset of the range of f(x) because f provides the final y values. 5. {(3, 4), (4, 1)} Other points of f don't have y values that are in the domain of g. The domain of g(f(x)) is {3, 4} which is a subset of the domain of f(x) because f(x) provides the initial x values (since it's the "inside function"). The range of g(f(x)) = {4, 1}.
First period is working on more Practice (Operations with Functions) and this worksheet was given to 6th and 7th as additional problems for review. Answers to this worksheet are:
1. (f+g)(x) = 8x2 + 5x - 13 and (f-g)(x) = 6x2 + 5x + 13
2. (f+g)(x) = 13x2 - 5x + 41 and (f-g)(x) = -13x2 - 5x + 41
3. (f+g)(x) = x2 - 20x/3 + 2 and (f-g)(x) = x2 + 22x/3 + 16
4. (f+g)(x) = 4x2 + 6 and (f-g)(x) = -21x2 + 6
5. (f*g)(x) = 105x + 25 and (f/g)(x) = 7x + 1
6. (f*g)(x) = 3x3 + 17x2 + 75x + 425 and (f/g)(x) = (x2 + 25)/(3x + 17) Where x doesn't equal -17/3
7. (f*g)(x) = x4 - 256 and (f/g)(x) = (x2 + 16)/(x2 - 16) where x doesn't equal 4 or -4
8. (f+g)(x) = -x + 8 9. (f-g)(x) = -3x - 12
10. (g-f)(x) = 3x + 12 11. (f*g)(x) = -2x2 - 22x - 20
12. (f/g)(x) = (-2x - 2)/(x + 10) for x not equal to -10
13. (g/f)(x) = (x+10)/(-2x - 2) for x not equal to -1
14. f(g(x)) = x and g(f(x)) = x
15. f(g(x)) = 4x2 - 4 and g(f(x) = 16x2 - 1
16. f(g(x)) = -x2 + 1 and g(f(x)) = -x2 + 1
17. -44 18. -52 19. -10
20. -5 21. -5 22. 22
23. -55 24. -28 25. 242