(D) should be the obvious answer
can u tell me what does the "symbol" in part "C" mean? I knew that D was the answer but didnt know what PART 3 meant.
see here: Fixed Point Theorem -- from Wolfram MathWorld
C means that there always exists a point such that or in other words intersects at least once (try to sketch a graph).
the answer is D, let .
I think the symbol stands for "there exists"