Let f(x)= x^2-1 and g(x)=2x-3
Find (g * f) (5)

Question

Let f(x)= x^2-1 and g(x)=2x-3
Find (g * f) (5)

lgbasallote · Answer

(g*f)(5) = g(5) * f(5)

g(5) = 2(5) - 3 = 10 - 3 = 7

f(5) = (5)^2 - 1 = 25 - 1 = 24

so g(5) * f(5) = 7 x 24

got it?

anonymous · Answer

Thats the answer i got also but there is not answer choice 168. I have -45 ,48, 5 and 45 as the choices. help ??!!

lgbasallote · Answer

wait...did it look like something like $$(f \quad o \quad g)(5)$$
or $$(f \cdot g)(5)$$

anonymous · Answer

(f   o   g ) (5)

anonymous · Answer

If I recall that's the same as f ( g (x) ), nested functions basically (one inside the other).  Formally it's pronounced: "f composed with g of x" or "f of g of x".

f(x)= x^2-1 and g(x)=2x-3
You input g(x) into f(x), and then put 5 in for x

Step 1:
f(g(x))= (2x-3)^2-1

Step 2:
f(g(5))= (2(5)-3)^2-1

anonymous · Answer

See if you get the answer now, and watch the order of operations here :-)

lgbasallote · Answer

sorry i had technnical difficulties but @agentx5 just said how to do it..

anonymous · Answer

^_^

anonymous · Answer

Im so lost. lol. Thanks for trying to help me.

anonymous · Answer

Yes. thats the answer choices.