Difference between revisions of "Square root property"

(First format)
(Second format)
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===Second format===
 
===Second format===
  
<math>(3x+4)^2=5</math> take the square root of both sides
+
<math>(3x+4)^2=5</math>  
<math>3x+4=\pm\sqrt{5}</math> isolate <math>x</math>
+
 
 +
take the square root of both sides
 +
 
 +
<math>3x+4=\pm\sqrt{5}</math>  
 +
 
 +
isolate <math>x</math>
 +
 
 
<math>x=\frac{\pm\sqrt{5}-4}{3}</math>
 
<math>x=\frac{\pm\sqrt{5}-4}{3}</math>
  
 
and those are the roots.
 
and those are the roots.

Revision as of 11:44, 15 May 2014

The square root property is a method for solving quadratic equations.

Method

First we must convert the quadratic to either the form $ax^2=b$ or $(yx+z)^2=w$.

First format

$x^2=18$

take the square root of both sides

$x=\pm\sqrt{18}$

so the roots are $\sqrt{18}$ and $-\sqrt{18}$.

Second format

$(3x+4)^2=5$

take the square root of both sides

$3x+4=\pm\sqrt{5}$

isolate $x$

$x=\frac{\pm\sqrt{5}-4}{3}$

and those are the roots.