Given the functions fx 7x 6 and a fogx b go0x c fofx d
Given the functions f{x) = 7x - 6 and = (a) {fog){x) = (b) (go/0(x) = (c) {fof)(x) = (d) (gog)(x) =
Solution
f(x) = 7x -6 , g(x) = -x2
a) (f o g)(x)
==> f(g(x))
==> f(-x2)
==> 7(-x2) -6
==> -7x2 - 6
Hence (f o g)(x) = -7x2 - 6
b) (g o f)(x)
==> g(f(x))
==> g(7x -6)
==> -(7x - 6)2
==> -(49x2 -84x + 36)
==> -49x2 + 84x - 36
Hence (g o f)(x) = -49x2 + 84x - 36
c) (f o f)(x)
==> f(f(x))
==> f(7x -6)
==> 7(7x -6) -6
==> 49x - 42 -6
==> 49x - 48
Hence (f o f)(x) = 49x - 48
d) (g o g)(x)
==> g(g(x))
==> g(-x2)
==> - (-x2)2
==> -x4
Hence (g o g)(x) = -x4
