Math Is Fun Forum

Staedtler

Guest

Quadratic equations Help!

how do i solve the quadratic equation

x^2-x=0

MathsIsFun

Administrator

Registered: 2005-01-21

Posts: 7,713

Re: Quadratic equations Help!

When does x^2=x ?

When x=0 and 1

Also Here: Plot of x^2-x

And here: Quadratic Equation Solver

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"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

Staedtler

Guest

Re: Quadratic equations Help!

Thanks for answering, but could you explain in more detail.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Quadratic equations Help!

Hi Staedtler;

If you understand factoring as a means of solving a quadratic then:

x^2 - x = 0 factors into x (x - 1) = 0 So:

Solve these 2 equations:
x=0 and x - 1 = 0

Both are easy and you get x = 0 and x = 1 as the roots.

Did you understand MathsisFun's advice that you should always graph your equation first? This is an important rule for later!

Last edited by bobbym (2009-11-15 22:13:09)

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Staedtler

Guest

Re: Quadratic equations Help!

Thanks i understand now, and yes i know how to graph too.
Thanks again!!

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Quadratic equations Help!

Hi Staedtler;

If I don't ramble once a day...

Ramblings:

That is sort of my point. Almost everyone favors the algebraic thrashing of the factoring method over graphing. With modern computers and pages like he recommends we shouldn't ignore the visual clues that a graph provides.

Also, I am kind of partial to the way he sent you to an automated solver to get your roots (http://www.mathsisfun.com/quadratic-equation-solver.html). That should be accepted in the modern school system because it is fast becoming the way everywhere else.

Last edited by bobbym (2009-11-15 22:48:46)

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.