Question

8. Which of the following correctly multiplies f(x) x g(x) if f(x) = 3x-1 and g(x) = 2x + 1?

A) f(x) x g(x) = 6x2 + x + 1
B) f(x) x g(x) = 5x
C) f(x) x g(x) = 6x2 + x-1
D) f(x) x g(x) = 5x2 + x-1

Answer 1

C) f(x) x g(x) = 6x2 + x-1

Explanation:

Multiplication of functions:

Two multiply two polynomial functions, we apply the distributive property(multiply each two terms and add).

In this question, we have that:

`f(x) = 3x - 1, g(x) = 2x + 1`

The multiplication is:

`f(x) * g(x) = (3x - 1)(2x+1) = 3x*2x + 3x*1 -1*2x -1*1 = 6x^2 + 3x - 2x - 1 = 6x^2 + x - 1`

The correct answer is given by option C.