College algebra

Question

given f(x)=2x^2-3 and g(x)=4x, find (g o f)(1)

Answer 1

Hello, thank you for taking the time to post your question!

The key on this type of question is to set up an algebraic expression that represents the information given in the question. On this one we have

(g o f)(1) = g(f(1))

f(1) = 2(1)^2 – 3 = 2 – 3 = -1

g(-1) = 4(-1) = -4

meaning that (g o f)(1) = -4

I hope that helps you get moving in a better direction on this type of question! Feel free to reach out if you have any additional questions beyond that :)

Answer 2

(g o f)(1) can be thought of as g(f(1)). Calculate f(1) then insert the result into g(x).

 

f(1) = 2*1^2 - 3 = 2 - 3 = -1

 

g(-1) = 4*(-1) = -4