sqaure root of 4

[vagarwal7]

I have a stupid q/s ..

In Manhattan guide says (Number properties i chapter 6 Roots strategy)

1. if √4 = x, then x =2

2. if x^2 = 4 then x= 2 or x= -2

I never understood point 1.. I always knew point 2
Please can someone explain

[mengnu.liang]

I read from many books that GMAT consider the square root of a number to be positive.

[tim]

yes. so when the GMAT writes the square root symbol, you only take the positive value. when you write the square root symbol as part of your calculations, the GMAT didn't put the symbol there so you have to account for both possible solutions..