求大神解答
Console.WriteLine(" 输入实数x和正整数n，求下列公式前n项之和。x-x^3/3!+ x^5/5! -x^7/7!…");
Console.Write("前n=");
long n = Convert.ToInt32(Console.ReadLine());
Console.Write("分母x=");
long x = Convert.ToInt32(Console.ReadLine());
double sum = 0, m = 1.0, t,a;
int i,p=1;
for (i = 1; i <= n; i+=2)
{
m *= i;
t = 2 * n - 1;
a =Math .Pow (x,t )/m;//x的t次方除以m
sum = sum + (p)*a ;
p = -p ;
}
Console.WriteLine("sum={0:f2}",sum);
Console.ReadLine();