题目大意：给6个系数，问是否存在X使得等式成立
思路：二分。。。。
#include <stdio.h>
#include <math.h>
#define EEE 2.71828182845953581496
int p, q, r, s, t, u;
double v(double x)
{
return (p*pow(EEE,-x)+q*sin(x)+r*cos(x)+s*tan(x)+t*x*x);
}
double f(double x,double z, double y)
{
double mid;
while((y-z)>1e-)
{
mid=(z+y)/;
if(v(mid)>x)
z=mid+1e-;
else
y=mid-1e-;
}
return mid;
}
int main()
{
while(~scanf("%d%d%d%d%d%d", &p, &q, &r, &s, &t, &u))
{
if(v()<-u||v()>-u)
printf("No solution\n");
else
printf("%.4lf\n", f(-u,,));
}
return ;
}