Question

Given f(x) = 4x^2 – 1 and g(x) = 2x - 1, find f(g(-1)).

Answer 1

Step-by-step explanation:

$f(x) = 4 {x}^{2} - 1 \: \: and \: \: g(x) = 2x - 1 \\ \\ \therefore \: g( - 1) = 2( - 1) - 1 = - 2 - 1 = - 3 \\ \\ \therefore \:f(g( - 1)) = 4( - 3) ^{2} - 1 \\ = 4 \times 9 - 1 \\ = 36 - 1 \\ = 35 \\ \\ \huge \red{ \boxed{\therefore \:f(g( - 1)) =35}}$

Answer 2

Answer:

35

Step-by-step explanation:

g(x) = 2x - 1

equate -1 into x

g(-1) = 2(-1)-1=-2-1=-3

f(x) = 4x²-1

equate g(-1)= -3 into x

f(g(-1))= f (-3) = 4(-3)²-1 = 4(9)-1 = 36-1 = 35