Answer :

To determine the value of the function [tex]\( f(x) = 2x^2 + 1 \)[/tex] when [tex]\( x = 3 \)[/tex], follow these steps:

1. Identify the function: The given function is [tex]\( f(x) = 2x^2 + 1 \)[/tex].

2. Substitute [tex]\( x = 3 \)[/tex] into the function: Replace [tex]\( x \)[/tex] with 3 in the function.
[tex]\[ f(3) = 2(3)^2 + 1 \][/tex]

3. Calculate [tex]\( 3^2 \)[/tex]: Compute the square of 3.
[tex]\[ 3^2 = 9 \][/tex]

4. Multiply by 2: Multiply the result by 2.
[tex]\[ 2 \times 9 = 18 \][/tex]

5. Add 1: Finally, add 1 to the product.
[tex]\[ 18 + 1 = 19 \][/tex]

Thus, the value of [tex]\( f(x) \)[/tex] when [tex]\( x = 3 \)[/tex] is [tex]\( 19 \)[/tex].

So, the correct answer is [tex]\( 19 \)[/tex].