Question

f(x) = 15x - 12
      g(x) = -15x2 + 14x - 10
      find g(g(7))

my brain hurts - help me through the steps - functions for dummies version, I have 7 problems to do
THANK YOU

Answer 1

g(7) = -15*7^2 + 14*7 - 10 = -647
g(g(7)) = g(-647)
= -15(-647)^2 + 14(-647) - 10 = -6,288,203

Not hard - just be careful with the arithmetic.

Answer 2

I don't get why f(x) = 15x - 12 is there then.?

Answer 3

can you help with these - still having problems

15. f(x) = -13x2 + 12x + 14 g(x) = 11x - 13
      find f(g(7))

16. f(x) = 11x + 15
     g(x) = -11x3 - 15x2 + 13x - 13
     find g(f(6))

17. f(x) = 15x3 + 13x2 - 15x + 15
     g(x) = 15x + 11
     find g(f(9))

18. f(x) = -13x2 - 13x + 14
     g(x) = -13x - 11
     find g(g(3))

19. f(x) = 15x + 12
     g(x) = -10x + 15
     find f(g(8))

Answer 4

is #15 -52,466???

Answer 5

15. yes

16.
f(6) = 11*6+15 = 81
g(81) = -11*81^3 - 15*81^2 + 12*81 - 13 = -5,943,307

17.
f(9) = 15*9^3 + 13*9^2 - 15*9 + 15 = 11,868
g(11868) = 15*11868 + 11 = 178,031

see? nothing to it!

Although all the big numbers are annoying. The arithmetic just gets in the way of the techniques.