# What is f(3) if f(x)=-x^2+7?

Sep 26, 2016

f(3) just means to substitute 3 in for x. $f \left(3\right) = - 2$

#### Explanation:

$f \left(3\right) = - {\left(3\right)}^{2} + 7$
According to the order of operations, first square the 3, which is 9.

$f \left(3\right) = - 9 + 7$
The negative sign in front of the x squared is equivalent to multiplying by negative one.

Add -9 and 7 together, which is -2
So, $f \left(3\right) = - 2$