Write an if/then.else primitive to do each of the following operations.

A.  Computer and display the value x divided by y if the value of y is
not 0.  If y does have the value 0, then display the message "unable
to perform the division."

B.  Computer the area and circumference of a circle given the radius r
if the radius is greater than or equal to 1.0; otherwise, you should
compute only the circumference.

A.
if (y !=0)
  printf ("%f", x/y)
else
  printf ("unable to perform the division.");

B.
if (r >= 1.0)
  printf ("area: %f\n", 2*pi*r);
printf ("circumference: %f", pi*r*r);

//The following is written in C++
#include <iostream>

using namespace std;

void partA(double x, double y)
{
	if(y != 0)
		cout << (x / y) << endl;
	else
		cout << "unable to perform the division." << endl;
}

void partB(double r)
{
	double results = 0.0; 
	double const PI = 3.14159;

	if(r >= 1.0) cout << "Radius = " << (PI * r * r) << endl;
	cout << "Circumference = " << (2 * r * PI) << endl;
}

A. 
/* This program is in 'c programming language  save it with .c extension*/
#include <stdio.h>
#include <conio.h>
void main()
{
      float x,y,d;
      clrscr();
      printf("Enter any value for x and y :");
      scanf("%f %f",&x,&y);
      if(y==0)
         printf("unable to perform the division.");
      else
      {
         d=x/y;
         printf(" Division = %f",d);
      }
      getch();
}


B.

/* This program is in 'c programming language  save it with .c extension*/
#include <stdio.h>
#include <conio.h>
void main()
{
      float radius,area,circum;
      clrscr();
      printf("Enter any value for radius:");
      scanf("%f",&radius);
      if(radius>=1.0)
       {
         area=3.14*radius*radius;
         circum=2*3.14*radius;
         printf("area = %f and circumference = %f",area,circum);
       }
      else
      {
         circum=2*3.14*radius;
         printf("circumference = %f",circum);
      }
      getch();
}