We are given the function $f(x) = 5 - 3x^2$ and asked to find the value of the function at $x=3$. This means we need to evaluate $f(3)$.

1. Problem Description

We are given the function $f(x) = 5 - 3x^2$ and asked to find the value of the function at $x=3$. This means we need to evaluate $f(3)$.

2. Solution Steps

To find $f(3)$, we substitute $x=3$ into the function $f(x)$.

$f(x) = 5 - 3x^2$

$f(3) = 5 - 3(3)^2$

First, evaluate the exponent:

$3^2 = 3 \times 3 = 9$

Substitute this back into the equation:

$f(3) = 5 - 3(9)$

Now perform the multiplication:

$3(9) = 27$

Substitute this back into the equation:

$f(3) = 5 - 27$

Finally, perform the subtraction:

$f(3) = -22$

3. Final Answer

$f(3) = -22$