// Andrew Taylor - andrewt@unsw.edu.au
// 6/3/2017

// A simple program to check Pythagorean identity

// Demonstrates danger of use == with doubles
// e.g. enter 1 for theta

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

int main(void) {
    double theta, identity;

    printf("Enter theta: ");
    scanf("%lf", &theta);

    identity = 1 - (sin(theta) * sin(theta) + cos(theta) * cos(theta));

    if (identity == 0.0) {
        printf("Pythagorean identity true for %lf\n", theta);
    } else {
        printf("Pythagorean wrong by %g for %lf\n", identity,  theta);
    }

    return 0;
}