Getting inverse sinus in degrees in c++

[NerdZilla]

Hi. I'm new to c++ but have programmed in java for a couple of months. I want
to make a program that calculates the refraction of Snell's law. Everthing
is fine but I can't inverse the sin (refraction) in degrees.
Is there possible way to do this?

#include <iostream>
#include <cmath>
using namespace std;

void AskI(){
    cout << "Pleas Enter The Angle Of Incidence" << endl;
}

void AskN(){
    cout << "Pleas Enter The Refractive Index" << endl;
}

double Proces (double I ,double N){
double Index = N;
double DegreeI = sin(I*3.14159265359/180);
double DegreeSinR = DegreeI/Index;
double DegreeR = sinh (DegreeSinR???)         :How To get the inverse sinus in               
                                               degrees?
   cout<< DegreeR << endl;

}

int main(){
double a;
double b;

AskI();
cin >> a;

AskN();
cin >> b;

Proces(a,b);
return 0;
}

[MiiNiPaa]

inverse sinus

Do you mean like 1/sin or arc sine?

for arc sine there is std::asin() function. As it returns value in radians, you should convert it to degrees after thst. like:

const double PI = 3.14159265358;
const double rad2deg = 180 / PI;
//...
double Degree = rad2deg * std::asin(value);

[mutexe]

double DegreeR = sinh (DegreeSinR???)

'sinh' to me implies hyperbolic sine. I'm not sure why you'd need this at all to work out angle of refraction, which i'm assuming you're trying to do?

I vaguely remember snell's law is just
[ sin(theta1)/sin(theta2) ] / [ n2/n1 ]

isn't it?

[NerdZilla]

Wel, the formula of snell's law is sini / sinr = n2 / n1
It doesn't work before you have the answer in degrees. In radians you can't
calculate it. But i tried MiiNiPaa's answer and it works perfectly now. thanks