Q. 91 - Precalculus Enhanced with Graphing Utilities

Question

In Problems 89–96, graph each equation using a graphing utility. Use a graphing utility to approximate the intercepts rounded to two decimal places. Use the TABLE feature to help to establish the viewing window.

$y=2x^2-15$

Step-by-Step Solution

Answer

The $x$ intercepts are $\left(-2.74,0\right)$ and $\left(2.74,0\right)$.

The $y$intercepts is $\left(0,-15\right)$

Step 1. Given Information

Given function is $y=2x^2-15$

Step 2. Create the table for values of x , y

$x$	$y=2x^2-15$
$-4$	17
width="23" height="20" style="max-width: none; vertical-align: -4px;" $-3$	3
$-2$	-7
$-1$	-13
$0$	-15
$1$	-13
$2$	-7

Step 3. Plot the points and connect them

Step 4. Finding x intercept

$$\begin{gathered} Put y=0 \\ 2x^2-15=0 \\ 2x^2=15 \\ {x}^2=7.5 \\ x=-2.74 or 2,74 \end{gathered}$$

Step 5. Finding y intercept

Put $x=0$

$$\begin{gathered} y=2x^2-15 \\ y=-15 \end{gathered}$$