Roots

[vananhtsang]

Hi there,

I have just purchased the quant series from MGMAT and find some confusion in the concept that written in the book about ROOTS. In chapter 4 of the Algebra book in the ROOTS chapter, states that:

"IF AN EQUATION CONTAINS A SQUARE ROOT, ONLY USE THE POSITIVE ROOT"

Ex: square root of 9 is 3

Should that be 3 and -3?

Thanks

[jnelson0612]

Hi there,

I have just purchased the quant series from MGMAT and find some confusion in the concept that written in the book about ROOTS. In chapter 4 of the Algebra book in the ROOTS chapter, states that:

"IF AN EQUATION CONTAINS A SQUARE ROOT, ONLY USE THE POSITIVE ROOT"

Ex: square root of 9 is 3

Should that be 3 and -3?

Thanks

Hi there,
No. This is an area of a lot of confusion. Let me try to clear it up!

Consider x^2 = 9. In this case x could be 3 or -3.

However, if you are taking the square root of 9, the GMAT considers that the positive root only, or 3.

I hope that this helps!