My question is why can't you square both sides of statement 2? You would then get x> yPosted from my mobile device
I presume, you mean to say that why can't we take square root of both sides of statement 2.
So here goes, the square root can lead to two values + or -. It is best explained by plugging in 2 numbers.
For example : x^2 = 9 and y^2 = 4
taking square-root, x= +3 or -3 and y = +2 or -2.
As you see here, if x=-3 and y=2 then x is not greater than y. Thus statement (ii) is insufficient and the answer is A (only statement i is sufficient).
You can take the square root of both sides of statement (2) if you do it properly.
and continue from here...
By definition, square root is always non-negative. But the quadratic equation
has two roots, 2 and -2.
, therefore x can be either 2 or -2.
Don't confuse taking the square root of a non-negative number with finding the roots of a quadratic equation.
It is incorrect to say "the square root can lead to two values + or -". There is no such a thing in mathematics.