Please Help me with this one problem!!!

Question

f(x)=2x 3 and g(x) = x2. (g*f)(x)

What would the answer be??

Please help!

Answer 1

First of all, to make g(f(x)) you are simply taking the formula f(x) and substituting it for the x in g(x) therefore:

If f(x) = 2x-3 then:

g(f(x)) = g(2x-3) = (2x-3)^2 = (2x-3)*(2x-3) = 4x^2-12x+9

If f(x) = 2x+3 then:

g(f(x)) = g(2x+3) = (2x+3)^2 = (2x+3)*(2x+3) = 4x^2+12x+9

Sorry, but I was not sure what the sign was. I hoped this helped; if the sign is something else, I can respond again.  

Answer 2

f(x) = 2x+3

g(x) = x^2

(g*f)(x) = (x^2)*(2x+3) = 2x^3 + 3x^2

If you meant (gof)(x), then

(gof)(x) = g(f(x)) = g(2x+3) = (2x+3)^2 = 4x^2 + 12x + 9