Question

Given $g\left(x\right)=-2x^2-9$, how do you find $g\left(3\right)$?

Answer 1

Finding the value of $g\left(3\right)$:

Given: $g\left(x\right)=-2x^2-9$.

To find $g\left(3\right)$ we just substitute $3$ in the place of $x$,

$\begin{array}{rcl}\therefore g\left(3\right)& =& -2{\left(3\right)}^2-9\\ & =& -2\left(9\right)-9\\ & =& -27\end{array}$

Hence, the value of $g\left(3\right)=-27$.