Question

What is the value of f(-2) if f(x) = - 3x2 + 4x - 1

Answer 1

Given the function below:

$\large{f(x) = - 3 {x}^{2} + 4x - 1}$

To find f(-2), we substitute x = -2 in the equation. Since f(-2) means the value of f(x) at x = -2.

$\large{f( - 2) = - 3 {( - 2)}^{2} + 4( - 2) - 1}$

Replace x-term to -2 and evaluate.

$\large{f( - 2) = - 3(4) - 8 - 1} \\ \large{f( - 2) = - 12 - 8 - 1 \longrightarrow f( - 2) = - 21}$

Answer

• f(-2) = -21

Let me know if you have any doubts!