To find $f(8)$ for the function $f(x) = 2x^2 - x - 12$, substitute $x = 8$ into the equation:

$f(8) = 2(8^2) - (8) - 12$

Calculate $8^2$:

$8^2 = 64$

Now substitute:

$f(8) = 2(64) - 8 - 12$

Calculate $2(64)$:

$2(64) = 128$

Now combine all the terms:

$f(8) = 128 - 8 - 12$ $f(8) = 128 - 20$ $f(8) = 108$

Thus, $f(8) = 108$.

Would you like any further details or have any questions? Here are some related questions you might consider:

1. How do you find the vertex of the quadratic function $f(x)$?
2. What are the roots of the equation $2x^2 - x - 12 = 0$?
3. How does the value of $f(x)$ change as $x$ increases?
4. What is the axis of symmetry for the function $f(x)$?
5. How would you graph the function $f(x) = 2x^2 - x - 12$?

Tip: To quickly evaluate quadratic functions, use the vertex form or complete the square for insights on their maximum or minimum values.