How to find g(f(5)) given f(x) = 2x - 3 and g(x) = x^2

How to find g(f(5)) given f(x) = 2x - 3 and g(x) = x^2 - 2?

Science & Mathematics by Anonymous 2018-05-25 14:06:22

Social Science

How to find g(f(5)) given f(x) = 2x - 3 and g(x) = x^2 - 2?

3 answers

I solved it as g(f(5)) = (5)^2 - 2 = 25 -2 = 23 but I realized that the f(5) part requires you to plug in the f(x) part and I can never do that correctly.

Anonymous

g(f(x)) = (2x - 3)^2 - 2 = 4x^2 - 12x + 9 - 2 = 4x^2 - 12x + 7 g(f(5)) = 4(5^2) - 12(5) + 7 = 100 - 60 + 7 = 47
Anonymous

g(f(5)) = (2(5) - 3)^2 - 2 = (10 - 3)^2 - 2 = 7^2 - 2 = 47. Final.
Anonymous

f(5) = 7 g(7) = 49-2 = 47