To evaluate the expression [tex]\(2x^2 - 1\)[/tex] when [tex]\(x = 3\)[/tex], follow these steps:
1. Substitute [tex]\(x = 3\)[/tex] into the expression:
[tex]\[
2(3)^2 - 1
\][/tex]
2. Calculate the exponent:
[tex]\[
3^2 = 9
\][/tex]
3. Multiply by 2:
[tex]\[
2 \cdot 9 = 18
\][/tex]
4. Subtract 1 from the result:
[tex]\[
18 - 1 = 17
\][/tex]
So, the value of [tex]\(2x^2 - 1\)[/tex] when [tex]\(x = 3\)[/tex] is [tex]\(\boxed{17}\)[/tex]. Hence, the correct answer is:
C. 17
