C Program To Check If Sum of Square of Sine and Cosine of an Angle is 1

Write a C program to receive value of an angle in degrees and check whether sum of squares of sine and cosine of this angle is equal to 1.

Related Read:
Basic Arithmetic Operations In C
Calculate Power of a Number using pow(): C Program

Formula To Convert Angle From Degree To Radian

radian = degree x ( PI / 180.0)
where PI is 3.14159265359

Note: In C programming Language, we’ve a builtin constant M_PI which has value of PI.

Expected Output for the Input

User Input:
Enter angle in Degree
45

Output:
Sum of square of sin(45.00) and cos(45.00) is 1

Logic To Check If Sum of Square of Sine and Cosine of an Angle is 1

User enters the angle in degree. We convert angle from degree to radian.
radian = degree x ( PI / 180.0)
Next we use pow() method present in math.h library to sqaure the values of sin(angle) and cos(angle). We add the square of sin(angle) and cos(angle) and store it inside the variable sum, and display appropriate message to the user.

Video Tutorial: C Program To Check If Sum of Square of Sine and Cosine of an Angle is 1

Source Code: C Program To Check If Sum of Square of Sine and Cosine of an Angle is 1

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

int main()
{
    float sum = 0, angle, temp;

    printf("Enter angle in Degree\n");
    scanf("%f", &angle);

    temp   = angle;

    angle  = angle * ( M_PI / 180.0 );

    sum    = (  pow(sin(angle), 2) + pow(cos(angle), 2)  );

    if(sum == 1)
    {
        printf("Sum of square of sin(%0.2f) and cos(%0.2f) is 1\n", temp, temp);
    }
    else
    {
        printf("Sum of square of sin(%0.2f) and cos(%0.2f) is not 1\n", temp, temp);
    }

    return 0;
}

Output 1:
Enter angle in Degree
30
Sum of square of sin(30.00) and cos(30.00) is 1

Output 2:
Enter angle in Degree
45
Sum of square of sin(45.00) and cos(45.00) is 1

Output 3:
Enter angle in Degree
60
Sum of square of sin(60.00) and cos(60.00) is 1

Output 4:
Enter angle in Degree
75
Sum of square of sin(75.00) and cos(75.00) is 1

Output 5:
Enter angle in Degree
90
Sum of square of sin(90.00) and cos(90.00) is 1

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