Problem Link

in the good function bool good(double x){ double temp=( x*x + sqrt(x) ); if(temp-c>0) return 0; else if(temp-c<=0) return 1; } why are we doing,

if(temp-c>0) return 0; else if(temp-c<=0) return 1;

instead of return temp-c== 0;

https://codeforces.com/edu/course/2/lesson/6/2/practice/contest/283932/problem/B

I was trying to solve this problem but I am getting wrong answer on test case 9 which I am unable to correct , please help,

here is my code link :