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?
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.1) x^2 is greater than 1.
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)
