Question

Let f(x) = x2 + x + 2 and g(x) = 2x + 5. Find f(g(x)). Show each step of your work. (10 points)

Answer 1

We were given;

f(x) = x² + x + 2

and

g(x) = 2x + 5

f(g(x)) = f(2x+5)

= (2x+5)²+(2x+5)+2

Expanding brackets gives;

=(2x)²+2(2x)(5) +5²+(2x+5)+2

Simplifying gives;

= 4x² +20x+25+ 2x+5+2

f(g(x))= 4x² +22x +32