Question

Given `f(x)=2x^{2}-9`, what is the value of `f(5)`?

Answer 1

To find the value of \( f(5) \) for the function \( f(x) = 2x^2 - 9 \), we substitute \( x = 5 \) into the function:

\[
f(5) = 2(5)^2 - 9
\]

First, calculate \( (5)^2 \):

\[
(5)^2 = 25
\]

Now, substitute this back into the equation:

\[
f(5) = 2 \times 25 - 9
\]

Next, calculate \( 2 \times 25 \):

\[
2 \times 25 = 50
\]

Now substitute that value in:

\[
f(5) = 50 - 9
\]

Finally, perform the subtraction:

\[
f(5) = 41
\]

Thus, the value of \( f(5) \) is \( \boxed{41} \).