win32 native console application

[muddaser]

i want ot insert trignomatric function in my calculator ..how to use trignomatric ratioes and get correct answar in c++ native win32 console application
plzz help me wd example

[Moschops]

The basic trig functions are found in <cmath>. Remember that we work in radians rather than degrees.

[muddaser]

how to exactly convert to radian?

[Moschops]

Divide by (2*pi/360)

[muddaser]

which value of pi i write?

[Moschops]

What's your favourite value of pi?

[muddaser]

when i insert 22/7 then it replies wrong .it says that cos 90 is equal to 1..thts wrong

[Moschops]

22/7 radians is not 90 degrees.

[muddaser]

i mean if i convrt degre to radian by putting value of pi as 22/7 then answars are wrong

[Moschops]

One of these things is true:

1) The universe has changed and cos and sin have different answers now.
2) Your code is wrong.
3) Your code is giving you a correct answer but you don't understand what it's saying.

I'm going to guess 2, but it could be 3.

[z05DSL3A]

#include <iostream>
#include <iomanip>
#include <cmath>

using namespace std;

int main ()
{

    cout << setprecision(20) << cos(90.0 * 2 * 3.14159265358979 / 360.0) << endl;
    cout << setiosflags(ios::fixed) << setprecision(20)<< cos(90.0 * 2 * 3.14159265358979 / 360.0) << endl;

    return 0;
}

[kbw]

22/7 is a poor substitute for PI. It's only used when you're doing all your calculations by hand.

acos(-1.0) should give you a good value for PI. This is because there are 2PI radians in a full circle. So a semi-circle has PI radians. cos(PI) is -1, so arc cos(-1) is PI. It's not obvious without a diagram of a unit circle.
http://pubs.opengroup.org/onlinepubs/007908799/xsh/acos.html