Question

If f(x)=2x+1 and g(x)=x2 find fg(3)​

Answer 1

Given:

The functions are:

$f(x)=2x+1$

$g(x)=x^2$

To find:

The value of $fg(3)$.

Solution:

We have,

$f(x)=2x+1$

$g(x)=x^2$

Substitute $x=3$ in each function.

$f(3)=2(3)+1$

$f(3)=6+1$

$f(3)=7$

And,

$g(3)=(3)^2$

$g(3)=9$

We know that, product of two functions is defined as:

$fg(x)=f(x)\times g(x)$

Using this rule, we get

$fg(3)=f(3)\times g(3)$

$fg(3)=7\times 9$

$fg(3)=63$

Therefore, the value of $fg(3)$ is 63.