Algebra Help - The Quadratic Formula - YourTeacher.com

For a complete lesson on the quadratic formula, go to http://www.yourteacher.com. Get the exact algebra help you need with 1000+ online math lessons featuring a personal math teacher inside every lesson! In this lesson, students learn to solve quadratic equations in the form ax^2 + bx + c = 0 using the quadratic formula, which states that x = -b plus or minus the square root of b^2 -- 4ac over 2a. For example, to solve the equation x^2 -- 3x -- 8 = 0, since a = 1, b = -3, and c = -8, the quadratic formula states that x = 3 plus or minus the square root of (-3)^2 -- 4(1)(-8) over 2(1). Simplifying on the right side of the equation, x = 3 plus or minus the square root of 9 + 32 over 2, or x = 3 plus or minus the square root of 41 over 2, which is the final answer. Note that students also learn to derive the quadratic formula using completing the square in the first example problem in this lesson.

Category:

Education

Tags:

• quadratic
• formula
• equation
• solving
• solve
• example

[TheBrandoXC]

Thumbs up if you always come here because your teacher can't teach worth shit and makes everything complicated!

[schusniper15]

HONESTLY WHEN THE HELL ARE WE GONNA NEED THIS IN LIFE?

WHY DO TEACHERS MAKE US LEARN SUCH POINTLESS SHIT?

LIKE IF YOU AGREE!

[Booth272]

@schusniper15 You're right, YOU will never need this because you will be working in the kitchen at McDonald's for the rest of your life.

[mushi1996]

oh ok but do we always choose the posotive number

[TheRealGrandGoon]

I love this dude. I just wish I can thank him in person.

[needsmetal]

what would 4x^2-3x-7=0 would be im having problems



[IssacSchneiderGin11]

i havent learn this yet.but you made it so easy.Thanks!

usually my teacher teach real slow as they are a few boys at the back of class that always complain and make the teacher repeat again and again.I got it right away,but i easily forget the formula.

[oOSignalzOo]

You lost me at to solve thi...

[Cockfist]

@schusniper15 I thought the same thing about math when I was younger, and now I can use math to build physical structures....I'm just a carpenter. Formulas in math are hard to see in reality sometimes.....but they're there. Think about the digits that'll be in your bank account when you're older, don't waste your time fighting the reasoning behind it....I did the same thing and had to re learn something I could have tried and picked up the first time.

[dinarvideos]

thanks for the help!

[yyyy2999]

Everyone says their teacher can't teach, but 99% of the time you just dont pay attention, or just dont to learn. If you dont know ask questions...I know because I was there.

[olubusayoenigma]

If this guy was invisible to everyone except for me and comes with me to school, I will have a 105% in my math class.