Find the GCD and LCM of Two Integers

#include

#include

void main()

    int num1, num2, gcd, lcm, remainder, numerator, denominator;

    clrscr();

    printf("Enter two numbers\n");

    scanf("%d %d", &num1, &num2);

    if (num1 > num2)

        numerator = num1;

        denominator = num2;

    else

        numerator = num2;

        denominator = num1;

    remainder = num1 % num2;

    while (remainder != 0)

        numerator   = denominator;

        denominator = remainder;

        remainder   = numerator % denominator;

    gcd = denominator;

    lcm = num1 * num2 / gcd;

    printf("GCD of %d and %d = %d\n", num1, num2, gcd);

    printf("LCM of %d and %d = %d\n", num1, num2, lcm);         getch();

Output

Enter two numbers

GCD of 30 and 40 = 30

LCM of 30 and 40 = 40

Calculate the Value of sin(x)

#include

#include

#include

#include

void main()

    int n, x1;

    float accuracy, term, denominator, x, sinx, sinval;

    clrscr();

    printf("Enter the value of x (in degrees) \n");

    scanf("%f", &x);

    x1 = x;

    x = x * (3.142 / 180.0);

    sinval = sin(x);

    printf("Enter the accuracy for the result \n");

    scanf("%f", &accuracy);

    term = x;

    sinx = term;

    n = 1;

do

        denominator = 2 * n * (2 * n + 1);

        term = -term * x * x / denominator;

        sinx = sinx + term;

        n = n + 1;

    } while (accuracy <= fabs(sinval - sinx));

    printf("Sum of the sine series = %f \n", sinx);

    printf("Using Library function sin(%d) = %f\n", x1, sin(x));

    getch();

Output

Enter the value of x (in degrees)

Enter the accuracy for the result

0.86602540378443864676372317075294

Sum of the sine series         = 0.855862

Using Library function sin(60) = 0.866093

Enter the value of x (in degrees)

Enter the accuracy for the result

0.70710678118654752440084436210485

Sum of the sine series         = 0.704723

Using Library function sin(45) = 0.707179

#include

#include

#include

#include

void main()

    int n, x1;

    float accuracy, term, denominator, x, cosx, cosval;

    clrscr();

    printf("Enter the value of x (in degrees) \n");

    scanf("%f", &x);

    x1 = x;

    x = x * (3.142 / 180.0);

    cosval = cos(x);

    printf("Enter the accuracy for the result \n");

    scanf("%f", &accuracy);

    term = 1;

    cosx = term;

    n = 1;

do

        denominator = 2 * n * (2 * n - 1);

        term = -term * x * x / denominator;

        cosx = cosx + term;

        n = n + 1;

    } while (accuracy <= fabs(cosval - cosx));

    printf("Sum of the cosine series = %f\n", cosx);

    printf("Using Library function cos(%d) = %f\n", x1, cos(x));

    getch();

Output

Enter the value of x (in degrees)

Enter the accuracy for the result

0.86602

Sum of the cosine series       = 0.451546

Using Library function cos(60) = 0.499882

Enter the value of x (in degrees)

Enter the accuracy for the result

0.7071

Sum of the cosine series       = 0.691495

Using Library function cos(45) = 0.707035

Check if a given Number is Prime number

#include

#include

#include

void main()

    int num, j, flag;

    clrscr();

    printf("Enter a number \n");

    scanf("%d", &num);

    if (num <= 1)

        printf("%d is not a prime numbers \n", num);

        exit(1);

    flag = 0;

    for (j = 2; j <= num / 2; j++)

        if ((num % j) == 0)

            flag = 1;

            break;

    if (flag == 0)

        printf("%d is a prime number \n", num);

     else

        printf("%d is not a prime number \n", num);

        getch();

Output

Enter a number

23 is a prime number

Enter a number

15 is not a prime number

Find Prime Numbers in a given Range

#include

#include

#include

void main()

    int num1, num2, i, j, flag, temp, count = 0;

    clrscr();

    printf("Enter the value of num1 and num2 \n");

    scanf("%d %d", &num1, &num2);

    if (num2 < 2)

        printf("There are no primes upto %d\n", num2);

        exit(0);

    printf("Prime numbers are \n");

    temp = num1;

    if ( num1 % 2 == 0)

        num1++;

    for (i = num1; i <= num2; i = i + 2)

        flag = 0;

        for (j = 2; j <= i / 2; j++)

            if ((i % j) == 0)

                flag = 1;

                break;

        if (flag == 0)

            printf("%d\n", i);

            count++;

    printf("Number of primes between %d & %d = %d\n", temp, num2, count);

getch();

Output

Enter the value of num1 and num2

70 85

Prime numbers are

Number of primes between 70 and 85 = 4