给定一个定义在[L,R]上的单调函数f(x)，求方程f(x)=0的根

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#include<cstdio>
#pragma warning(disable:4996)

//给定一个定义在[L,R]上的单调函数f(x)=x^2-2，求方程f(x)=0的根，即根号2的值
const double eps = 1e-5; //精度要求eps是10^-5

double f(double x) {
	return x * x - 2;
}

double solve(double L, double R) {
	double left = L, right = R, mid = 0;
	//还没达到精度要求就继续计算
	while (right - left > eps) { 
		mid = left + (right - left) / 2;
		if (f(mid) > 0) {  //f(mid)大于0，进入[left,mid]查找
			right = mid;
		}
		else {	//f(mid)小于等于0，进入[mid,right]查找
			left = mid;
		}
	}
	return mid; //mid就是f(x)=0在[1,2]区间内的根
}

int main() {	
	printf("%f", solve(1, 2)); //区间[1,2]

	return 0;
}