OJ Board

Hello,I get WA many times.
But I really don't know what's wrong in this code.
I think it should be a stupid mistake, but I can't find it....
help me if you can,thank you~

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>

//p*e-x + q*sin(x) + r*cos(x) + s*tan(x) + t*x2 ...