Quadratic Formula

You can use this formula to find the solutions(roots) to a quadratic equation.

2 4

2

b b ac

a

This formula can be broken up into 2 parts:

b2 – 4ac is called the Discriminant. It can tell you what the roots look like.

Find the Discriminant and describe the type of roots:y = 3x2 + 5x – 4

a = 3b = 5 c = -4

(5)2 – 4(3)(-4) =25 + 48 =73

2 real roots

Practice finding the discriminant 5x2 + 20x + 21 = 0

Quadratic Formula

You can use this formula to find the solutions(roots) to a quadratic equation.

2 4

2

b b ac

a

This formula can be broken up into 2 parts:

b2 – 4ac is called the Discriminant. It can tell you what the roots look like.

Find the Discriminant and and solve for the roots:y = 3x2 + 5x – 4

a = 3b = 5 c = -4

(5)2 – 4(3)(-4) =25 + 48 =73

2 real roots

5 73 5 73

2 3 6 6

Solving the roots:y = 2x2 – 3x + 6

a = 2b = -3c = 6

9 – 48 =- 39

3 39

4

3 39

4 4i

Practice solving: 3 – 8v – 5v2 = 2v s2 – s – 3 = s