The Quadratic Formula

When can I use it?!?!?

• Anytime!• In place of factoring• In place of solving using square roots• Pros and Cons to using it though

Pros of the Quadratic Formula

• It can be used anytime• Sometimes it is not possible to factor, so the quadratic

formula will still let you solve the problem• When you don’t know what to do, use it!

Cons of the quadratic formula

• When it is possible to factor, factoring is faster and the quadratic formula could slow you down.• Easy to make mistakes when using the quadratic formula

Common errors/things to look out for!• There are two solutions to the quadratic formula• Watch out for negative signs• Make sure you put the equation in standard form• ax2+bx+c

a

acbb

2

42

Steps for solving

• Put the equation in standard form• Identify a, b, and c coefficients• Plug into the formula• Solve for the positive and negative solutions

Solve 2k2+9k=-7

Solve 5r2=80

Solve 2x2-36=x

Solve 5x2+9x=-4

Solve k2-31-2k=-6-3k2-2k