OG QR 2nd Ed. DS #81

[tofubeans]

Is x^2 greater than x?

1) x^2 is greater than 1.

2) x is greater than -1.

Solution: A

[neelgandham]

Is x^2 greater than x?

Before I answer the question, I would like to rephrase the question.

Is x^2 > x ?
Is x^2-x > 0 ?
Is x(x-1)> 0 ? The value of x(x-1) is greater than 0, only if x<0 or x>1. So, the question can be rephrased to Is x<0 or x>1?

1) x^2 is greater than 1.

x^2>1. Implies that x>1 or x<1. So x is definitely <0 or >1. Statement I is sufficient to answer the question.

2) x is greater than -1.

x>-1, doesn't always imply that x>1 as the value of x can be between 0 and 1 as well.(try substituting x=1/2 and x=2)

[pemdas]

this question is tricky, it's tempting e, but indeed it's a
prompt: Is |x|>|sqrt(x)| the bold part is very important, as the value under square root can be only positive, but then we have mod as well. Hence statement(1) offers the right set along with x>1 or x<-1.

Is x^2 greater than x?

1) x^2 is greater than 1.

2) x is greater than -1.

Solution: A

[ronnie1985]

x^2-x>0 is the question
It is translated to x(x-1)>0 which => x>1 or x<0

S1. x^2>1=> x>1 or x<-1 which satisfies the above conditions for x^2-x>0
Sufficient

S2. x>-1, if x=0 x^2=x and if x=2, x^2>x. Not Sufficient.

[spartacus1412]

A alone is sufficient.