# Math Help - Functions question

1. ## Functions question

2. (D) should be the obvious answer

3. 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.

thanks

4. Originally Posted by champrock
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.

thanks
hi,

see here: Fixed Point Theorem -- from Wolfram MathWorld
C means that there always exists a point $x_{0}\in[0,1]$such that $f(x_{0})=x_{0}$ or in other words $=f(x)$ intersects $y=x$ at least once (try to sketch a graph).
the answer is D, let $f(x)\equiv1/2$.

5. I think the symbol stands for "there exists"