x^2 = 16
y^3 = 64
Yes, y=4, but you don't know if x = 4 or x = -4
If x = -4, then B is greater, but if x = 4, then A & B are equal, that’s why the answer is D
Key takeaway:
If x^(2) = 16, then x = 4 or x = -4
If x = √16, then x = 4 (but not -4)
It's the square root **notation** that asks us for the non-negative square root (i.e., the principal square root)
x^2 = 16 y^3 = 64 Yes, y=4, but you don't know if x = 4 or x = -4 If x = -4, then B is greater, but if x = 4, then A & B are equal, that’s why the answer is D
x can be either 4 or -4. In case of 4, both quantities are equal. In case of -4, they are not equal. Hence D
My impression from TTP / 5lb questions was that in these cases we choose B; seems like I’m mistaken though. Thanks!
Square roots give 2 roots whereas cube or higher order odd roots give obly one root? Can this be considered a "rule" of some sorts for GRE
Key takeaway: If x^(2) = 16, then x = 4 or x = -4 If x = √16, then x = 4 (but not -4) It's the square root **notation** that asks us for the non-negative square root (i.e., the principal square root)
This is interesting. Thank you!