Solving Quadratic Equations - Cool math Algebra Help Lessons

$Cool math fractal$

Your browser does not support the IFRAME tag.

$cool math anxiety survival and success guide$ $cool geometry art - fractals, polyhedra, more$ $other math stuff$
$cool math lessons$ $cool math games and practice problems$ $cool math games$ $free online math dictionary$
$Cool Math 4 Kids$

Coolmath Algebra
Solving Quadratics Lesson 5 - The Quadratic Formula (Quadranator)
(page 3 of 4)
---- This algebra lesson explains how to solve quadratic equations using the quadratic formula.

Your browser does not support the IFRAME tag.

	Your browser does not support the IFRAME tag.


Graphing Calculator	Scientific Calculator	<< a new window will open for these

Here's one that doesn't factor:

Solve

x = -b +/- sqrt( b^2 - 4ac ) / 2a = -1 +/- sqrt( ( 1 )^2 - 4 ( 1 ) ( -1 ) ) /( 2 ( 1) ) = -1 +/- sqrt( 1 + 4 ) / 2 = -1 +/- sqrt( 5 ) / 2

So x = -1 - sqrt( 5 ) / 2 or x = -1 + sqrt( 5 ) / 2

Yep -- these messy little buggers are the answers:

{ -1 - sqrt( 5 ) / 2 , -1 + sqrt( 5 ) / 2 }

If you were in a science or business class, you'd need to pop these into your calculator to get decimal approximations for these. Since you may need to do this someday, we better practice this. Since all calculators are different, it won't do much good for me to tell you how to enter this in... So, you're on your own. Here are the answers:

exact: { -1 - sqrt( 5 ) / 2 , -1 + sqrt( 5 ) / 2 }

decimal approximation: { -1.618 , .618 }

Find out which of these your teacher wants.

Continued on the next page

The printing and distribution and/or downloading of these lessons is strictly prohibited.


Graphing Calculator	Scientific Calculator	<< a new window will open for these

||||| copyrights and fair use of these lessons |||||

.....::::::::::::::: HELP SUPPORT COOLMATH :::::::::::::::.....
::::::: link to us ::::::: advertise with us ::::::: why we have ads ::::::: cool math games store :::::::

|| about us || about our Cool Math Games || safe surfing || privacy policy || terms of use || copyrights & fair use ||

|| cool math pre-algebra || cool math algebra || cool math precalculus / calculus || cool math anxiety survival || geometry / art / fractals / polyhedra ||
|| free online brain bender and jigsaw puzzles || cool math books || other math stuff ||

|| cool math lessons: how to... || cool math games & practice problems || cool math 4 kids lessons and games || cool math games for arithmetic ||
|| free online math dictionary || geometry / trigonometry reference || cool math for teachers || cool math for parents || cool math games ||

|| Coolified Games || Cool Math 4 kids || Spike's Game Zone || Finance Freak || Totally Stressed Out || Science Monster lessons ||