Question

if $f(x) = 2x^2 + 1$, what is $f(x)$ when $x = 3$?
\bigcirc\\ 1
\bigcirc\\ 7
\bigcirc\\ 13
\bigcirc\\ 19

Explanation:

Step1: Substitute \( x = 3 \) into the function \( f(x)=2x^{2}+1 \)

First, calculate \( x^{2} \) when \( x = 3 \), so \( 3^{2}=9 \).

Step2: Calculate \( 2x^{2} \)

Multiply the result from Step 1 by 2: \( 2\times9 = 18 \).

Step3: Add 1 to the result from Step 2

Add 1 to 18: \( 18 + 1=19 \).

Answer:

19 (corresponding to the option "19")