Question

If f(x)=3x²-1 and g(x)= x+2, find (f+g)(x).

O
A. 3x3 - 2
B. 3x²+x+1
C. 4x² +1
D. 3x²+x-1

Answer 1

(f + g)(x) = 3x² + x + 1

Explanation:

`\displaystyle{(f+g)(x) = f(x)+g(x)}`

Substitute f(x) = 3x² - 1 and g(x) = x + 2 in:

`\displaystyle{f(x)+g(x) = (3x^2-1)+(x+2)}\\\\\displaystyle{f(x)+g(x)=3x^2-1+x+2}\\\\\displaystyle{f(x)+g(x) = 3x^2+x+1}\\\\\displaystyle{\therefore (f+g)(x) = 3x^2+x+1}`