Solving Quadratic Formula

using the discriminant

2

2

4ab

a

bx

c

Quadratic formula using the discriminant

Examples:

Step 1: Write equation in Standard Form

Ax² + Bx + C = 0

x² + 4x + 3 = 04x² + 8x + 3 = 03x² + 6x = 0

Quadratic formula using the discriminant

Step 2: Find A,B and C x² + 4x + 3 =

0 C= 3

3x² + 6x = 0

A=3 B= 6 C= 0

4x² + 8x + 3 = 0A=4 B= 8 C= 3

A=1 B= 4

Quadratic formula using the discriminant

2

2

4ab

a

bx

c

Is the discriminant.

If b²-4ac is positive, then the equation has 2 answers.

If b²-4ac is 0, then the equation has 1 answer.

If b²-4ac is negative, then the equation has no real solution.

Rational

Irrational

Rational

Solving Quadratic Equations by using Graphing Calculator

CW Problem # 15 28 2209

15

When you enter the expression into the calculator your going to have to use double parenthesis.

Then use 2nd enter to get the minus answer.