Functions arcsin and arccos are not working properly

Question

I need to write the code for solving a simple equation, which should contain arcsin and arccos.

Formulas

F = cos^2(p(x)) + sin^2(p(y) + p(z)
p(k) = arccos(a * k) + arcsin(k)

Here is the code I wrote for solving it, but it gives -nan Ind as output. However, when I fix acos and asin to just cos and sin, everything works.

Expected input:

x = 1.20
y = 3.05
z = 2.00

Code

#include <iostream>
#include <math.h>

using namespace std;

const double a = 0.01;

double p(double k) {
    double p1;
    p1 = acos(a * k) + asin(k);
    return (p1);
}

int main() {
    double x;
    double y;
    double z;
    double F;

    cout << "x = "; cin >> x;
    cout << "y = "; cin >> y;
    cout << "z = "; cin >> z;

    F = pow(cos(p(x)), 2) + pow(sin(p(y)), 2) + p(z);

    cout << "F = " << F << endl;

    return 0;
}

Answer 1

The OUTPUT range of SIN and COS is [-1, +1]. That means the INPUT range of ARC (inverse) sin is [-1, +1]. You are trying to do asin(1.2), which probably yields NaN.