# Square Root Problem

• May 1st 2011, 05:34 PM
gurrry
Square Root Problem
We are nearing the end of my algebra class.. I understand almost everything. I am currently doing a review, but I am not sure what to do for this problem..

Above the equation it says to use the discriminant to solve, but I dont believe this is a discriminant problem

Im not sure how to write it out regularly, so I will try my best.

Problem:

The square root of... 9x^2 - 12x + 4

Ive tried breaking down each # and variable seperatley but I dont understand how we are supposed to get to this answer:

Absolute Value of 3x - 2

Does anyone know what to do?
• May 1st 2011, 05:38 PM
TheChaz
Quote:

Originally Posted by gurrry
We are nearing the end of my algebra class.. I understand almost everything. I am currently doing a review, but I am not sure what to do for this problem..

Above the equation it says to use the discriminant to solve, but I dont believe this is a discriminant problem

Im not sure how to write it out regularly, so I will try my best.

Problem:

The square root of... 9x^2 - 12x + 4

Ive tried breaking down each # and variable seperatley but I dont understand how we are supposed to get to this answer:

Absolute Value of 3x - 2

Does anyone know what to do?

(I'll ignore the discriminant part...)

Take (3x - 2).
Square it.
(3x - 2)^2 = 9x^2 - 12x + 4, which is exactly what you have under the radical.

Now √(A^2) IS NOT (just) "A"!!!!!!!!!!!!!!!!

It is the Absolute Value of A. Some even define the absolute value in this way.
• May 1st 2011, 05:41 PM
gurrry
Quote:

Originally Posted by TheChaz
(I'll ignore the discriminant part...)

Take (3x - 2).
Square it.
(3x - 2)^2 = 9x^2 - 12x + 4, which is exactly what you have under the radical.

Now √(A^2) IS NOT (just) "A"!!!!!!!!!!!!!!!!

It is the Absolute Value of A. Some even define the absolute value in this way.

So basically I just needed to factor what was underneath the radical?
• May 1st 2011, 05:43 PM
Quacky
Edit: Just to reference the discriminant part again, have you worked out the discriminant?

It's: \$\displaystyle 12^2-4(9)(4)=0\$

• May 1st 2011, 05:45 PM
gurrry
Quote:

Originally Posted by Quacky
Edit: Just to reference the discriminant part again, have you worked out the discriminant?

It's: \$\displaystyle 12^2-4(9)(4)=0\$