# How do use the discriminant to find all values of c for which the equation #2x^2+5x+c=0# has two real roots?

##### 1 Answer

Feb 21, 2017

#### Answer:

I tried this:

#### Explanation:

We need the discriminant to be greater then zero to have two different real roots (if it is equal to zero you'll have two coincident real roots). So we need:

where we use the convention for the general form of our equation where:

we get:

rearranging:

and

You can test your result by setting:

it'll give you

it'll give you

it'll give you