# How do you solve x^2-x-4=0 graphically?

##### 1 Answer
Sep 4, 2016

From the graph we get $x \approx - 1.6 \mathmr{and} x \approx 2.6$
We cannot find the exact answer graphically.

#### Explanation:

First you need to draw the graph of the parabola as
$y = {x}^{2} - x - 4$

You can do this by plotting points.
Draw up a table, choose some x-values and work out the y-values.

If you compare $\textcolor{red}{y} = {x}^{2} - x - 4$ and ${x}^{2} - x - 4 = \textcolor{red}{0}$, you will see that the only difference is that $y = 0$

$y = 0$ is the equation of the x-axis. The question is asking..

"Where does the parabola intersect the x-axis?"
OR
What are the x-intercepts for this graph?"
OR
Find the roots of the equation $0 = {x}^{2} - x - 4$

From the graph we get $x \approx - 1.6 \mathmr{and} x \approx 2.6$
We cannot find the exact answer graphically.

graph{x^2-x-4 [-2.365, 2.635, -1.62, 0.88]}