C语言实现一元二次方程求根

题目：输入一元二次方程的三个系数，并输出对应的实根

#include 
#include  //用于求开方的函数sqrt在math.h头文件中

int main()
{
	double a, b, c;
	double delta, x1, x2;

	scanf("%lf%lf%lf", &a, &b, &c);

	delta = b * b - 4 * a * c;

	if (delta > 0)
	{
		x1 = (-b + sqrt(delta)) / (2 * a);
		x2 = (-b - sqrt(delta)) / (2 * a);
		printf("x1 = %f, x2 = %fn", x1, x2);
	}

	else if (delta == 0)
	{
		x1 = -b / (2 * a);
		x2 = x1;
		printf("x1 = x2 = %fn", x1);
	}
	else
		printf("Unsolvable!n");

	return 0;
}