Question

c语言编程 cos(x)=1-x^2/2!+x^3/3!-x^4/4!+......-x^10/10!

具体题目如下： 输入x，按下列公式计算cos(x)的近似值。
cos(x)=1-x^2/2!+x^3/3!-x^4/4!+......-x^10/10!

Answer 1

# include <stdio.h>
void main()
{
int i,j,m=1,t=1;
double x, n, sum=1;
printf("请输入x：\n");
scanf("%f",&x);
for(i=2;i<11;i++)
{
for(j=2,n=x;j<=i;j++)
{
m=m*j;
n=n*x;
}
t=-t;
sum+=t*n/m;
}
printf("cos(%f)=%f\n",x,sum);
}

Answer 2

看一下吧 这样写OK吧
double cos(double x)
{
double a;
double b = 1;
double sum = 1 ;
for (int i = 2 ; i <= 10 ; i++)
{
a = 1 ;
for (int j = 1 ; j <= i ; j++)
{
b = b * x ; // 求次方
a = a * j ; // 求阶乘
}
if (i % 2 == 0)
{
sum += (-( b / a));
}
else
{
sum += (b / a);
}
}

return sum;

}