If f(x) = 3x2 + 1 and g(x) = 1 – x, what is the value of (f – g)(2)?

Question

If f(x) = 3x2 + 1 and g(x) = 1 – x, what is the value of (f – g)(2)?

Answer 1

You subtract the two functions then substitute the 2 in.

(f-g)(x)=(3x²+1)-(1-x)=3x²+1-1+x=3x²+x

Now substitute the 2 in for x: 

(f-g)(2)=3(2)²+2=3(4)+2=14