函数名: sqrt
功 能: 计算平方根
用 法: #include <math.h>
double sqrt(double x);
程序例:
#include <math.h>
#include <stdio.h>
int main(void)
{
double x = 4.0, result;
result = sqrt(x);
printf("The square root of %lf is %lf\n", x, result);
return 0;
}