prog_lab_2.2

#include <stdio.h>
#include <math.h>
int main(void) {
    int operation, n;
    float a, b, res;
    while(1) {
       printf("\n1st value: ");
       scanf("%f",&res);
       n=1;
       while(n) {
          printf("\nOperation: ");
          scanf("%i",&operation);
          if(operation>=2&&operation<=5)
          {
             printf("\nValue: ");
             scanf("%f",&b);
          }
          switch(operation){
            case 1: n=0; break;
            case 2: res=res+b; break;
            case 3: res=res-b; break;
            case 4: res=res*b; break;
            case 5: res=res/b; break;
            case 6: res=res/tan(a); break;
            case 7: res=fabs(res); break;
            case 8: res=pow(res,3); break;
            case 9: return 0;
            default: printf("\nInvalid operation number!"); break;
          }
          if(operation>=2&&operation<=8) printf("\nResult: %.3f\n", res);
       }
    }
}