# How do you find all the zeros of  f(x)= x^2-2x-4?

Feb 27, 2016

$- 1.236 \mathmr{and} 3.236$

#### Explanation:

Use the quadratic formula to find points where $f \left(x\right) = 0$.

This occurs when $x = \frac{- \left(- 2\right) \pm \sqrt{{2}^{2} - 4 \left(1\right) \left(- 4\right)}}{\left(2\right) \left(1\right)}$

$= \frac{2 \pm \sqrt{20}}{2}$

$= - 1.236 \mathmr{and} 3.236$.

We may verify this by plotting the graph of the function :

graph{x^2-2x-4 [-10, 10, -4.996, 5.005]}