#include<stdio.h>
#include<conio.h>
#include<math.h>
float deQuy(float x, int n)
{
if(n == 1)
{
return x * x;
}
return deQuy(x, n - 1) + pow(x,2 * n);
}
float deQuyDuoi(float x, int n, float y = 0)
{
if(n == 0)
return y;
return deQuyDuoi(x, n - 1, y + pow(x,2 * n));
}
float khuDeQuy(float x, int n)
{
float tong = 0;
for(int i = 1; i <= n; i++)
{
tong += pow(x, 2 * i);
}
return tong;
}
int main()
{
float x;
int n;
printf("\nNhap x: "); scanf("%f", &x);
printf("\nNhap n: "); scanf("%d", &n);
printf("\nDe quy(%f, %d) = %f", x, n, deQuy(x, n));
printf("\nKhu de quy(%f, %d) = %f", x, n, khuDeQuy(x, n));
printf("\nDe quy duoi(%f, %d) = %f", x, n, deQuyDuoi(x, n));
getch();
return 0;
}