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 $\boxed{{\displaystyle 41}}$.