Q. 1 - Precalculus Enhanced with Graphing Utilities

Question

Find $f\left(3\right)$ if $f\left(x\right)=-4x^2+5x$.

Step-by-Step Solution

Answer

The value of $f\left(3\right)=-21$.

Step 1. Given Information

The given function is :

$f\left(x\right)=-4x^2+5x$

Step 2. Substitute the value of x = 3 .

The value of $f\left(3\right)$ is

$\begin{array}{rcl}f\left(3\right)& =& -4\times 3^2+5\times 3\\ f\left(3\right)& =& -4\times 9+15\\ f\left(3\right)& =& -36+15\\ f\left(3\right)& =& -21\end{array}$