Hello
I got very confused with one of the questions in OG. I am not posting the question here, but its variation to understand the answer choice.
Is 2^x + 2^-x = b ? x being an integer
one of the answer choice says......x>0 = b
what does that mean does that mean
1. x > 0 and x = b
or 2. x > 0 and 0 = b...i think this is right..
if the second is right, then for any value of x which is more than 0, 2^x + 2^-x can never be 0. so its sufficient. However the book says its insufficient. Please clarify.