2.请补充例5. 7程序,分别统计当“fabs(t)>= le- 6”和“fabs(t)> = le- 8”时执行循环体的次数。

fabs(t)>= le- 6 ，示例代码

# include <stdio.h>
# include <math.h>

int main()
{
	int sign = 1;
	double pi = 0.0, term = 1.0;
	int n = 0;

	while (fabs(term) >= 1e-6)
	{
		n++;
		term = 1.0 / (2 * n - 1)*sign;
		pi += term;
		sign = -sign;
	}
	pi *= 4;
	printf("pi的近似值是%lf\n", pi);
	printf("循环体循环了%d次\n", n);
	return 0;
}

运行截图：

fabs(t)> = le- 8，示例代码

# include <stdio.h>
# include <math.h>

int main()
{
	int sign = 1;
	double pi = 0.0, term = 1.0;
	int n = 0;

	while (fabs(term) >= 1e-8)
	{
		n++;
		term = 1.0 / (2 * n - 1)*sign;
		pi += term;
		sign = -sign;
	}
	pi *= 4;
	printf("pi的近似值是%lf\n", pi);
	printf("循环体循环了%d次\n", n);
	return 0;
}

运行截图：