Question

Let f(x) = 5x - 4 and g(x) = x^2- 1. Find (g•f)(0).

Answer 1

Answer:

$(g\cdot f)(0)=4$

Step-by-step explanation:

So we have the two functions:

$f(x)=5x-4\text{ and } g(x)=x^2-1$

And we want to find:

$(g\cdot f)(0)$

This is the same as:

$=g(0)\cdot f(0)$

So, find g(0) and f(0):

g(0):

Substitute 0 into g(x):

$g(0)=(0)^2-1$

Square:

$g(0)=0-1$

Subtract:

$g(0)=-1$

And f(0):

Substitute 0 into f(x):

$f(0)=5(0)-4$

Multiply:

$f(0)=0-4$

Subtract:

$f(0)=-4$

So, our equation is now:

$(g\cdot f)(0)=g(0)\cdot f(0)=(-1)\cdot(-4)$

Multiply:

$=4$

So, our answer is 4.

And we're done!