Question 717110: f(x)=x+3 and g(x)= x^2-1
I need help with these 2 problems. (f+g)(3) and (f*g)(-2)
Thanks for all the help! Answer by nerdybill(7384) (Show Source):
You can put this solution on YOUR website! f(x)=x+3 and g(x)= x^2-1
.
(f+g)(x) = x+3 + x^2-1
(f+g)(x) = x+2 + x^2
(f+g)(x) = x^2+x+2
so,
(f+g)(3) = 3^2+3+2
(f+g)(3) = 9+3+2
(f+g)(3) = 14
.
(f*g)(x) = (x+3)(x^2-1)
(f*g)(x) = x^3-x+3x^2-3
(f*g)(x) = x^3+3x^2-x-3
so,
(f*g)(-2) = (-2)^3+3(-2)^2-(-2)-3
(f*g)(-2) = -8+3(4)+2-3
(f*g)(-2) = -8+12+2-3
(f*g)(-2) = 3
