Question

If f(x) = 2x2 + 1, what is f(x) when x = 3?

Answer 1

we have the function f(x)

$f(x)=2x^2+1$

For x=3

substitute in the function above

$\begin{gathered} f(x)=2x^2+1 \\ f(3)=2(3^2)+1 \\ f(3)=18+1 \\ f(3)=19 \end{gathered}$

therefore

the answer is 19