Originally Posted by

**GIPC** Hmm, thanks. Interesting, the former poster suggested splitting f for odd and even and you split it for x<0 and x>0

Some follow up questions:

On what do you base now that f is single value? What is the formal explanation?

And you've noted that

"The extreme values will be taken at the ends of the interval of convergence. Is the greatest value of the function greater than 1.5, and is the least value less than –0.5? If so, then it must take each of those two values exactly once."

On what do you base this, what theorem? Why does f take each of those values once?