3laba

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

int main() {
  float EPS = 0;
  long double EP = 1;
  long double x = 0;
  printf("Enter EPS(0 < EPS < 1) = ");
    if(scanf("%f", &EPS) != 1)
    {
        printf("Error.\n");
        return 0;
    }
  printf("Enter x = ");
    if(scanf("%Lf", &x) != 1)
    {
        printf("Error.\n");
        return 0;
    }
  long double y = 1;
  long double powx = x*x*(-1);
  long double powxOld = powx;
  long int factorial = 2;
  long int factorialOld = factorial;
  long int f = 2;
  if(EPS >= 1 || EPS <= 0)
  {
    printf("Error EPS.\n");
    return 0;
  }
  int k = 0;
  printf("cos(x) = %f;\n", cos(x));
  while(fabsl(EP) > EPS) // В зависимости от компилятора, если будет выдавать ошибку попробуй вместо fabsl fabs
  {
    EP = (long double) powx/factorial;
    y = y + EP;
    powx = powx*x*x*(-1);
    factorial = factorial*(f + 1)*(f + 2);
    if(factorial < factorialOld || fabsl(powx) < powxOld)
    {
      printf("OverFlow\n");
      return 0;
    }
    factorialOld = factorial;
    powxOld = powx;
    f = f + 2;
    k++;
  }
  printf("Teilor = %Lf\n", y);



  return 0;
}