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


double intoRadians(double fdegree);

double trygonometric_calc(double fdegree, int func_choiсe);


int main()
{
    int func_choice;
    double degree;

    puts("Choice the function to calculate(1 - sin, 2 - cos, 3 - tan, 4 - cot):");
    // Почитай почему %u
    scanf("%u", &func_choice);

    puts("Enter the degree:");
    scanf("%lf", &degree);

    printf("Result: %lf", trygonometric_calc(degree, func_choice));

    system("pause");

    return 0;
}

double intoRadians(double fdegree)
{
    return (fdegree * 3.14) / 180;
}

double trygonometric_calc(double fdegree, int func_choice)
{
    if ( (func_choice > 4) || (func_choice < 1))
    {
        puts("Invalid input");
        exit(0);
    }

    switch (func_choice)
    {
        case 1:
            return sin(intoRadians(fdegree));

        case 2:
            return cos(intoRadians(fdegree));

        case 3:
            return tan(intoRadians(fdegree));

        case 4:
            return 1 / tan(intoRadians(fdegree));

    }
}