The acos() function is defined in valarray header file. This function is used to calculate arc cosine of the value of each element in valarray and returns a valarray containing the arc cosine of all the elements.
Syntax:
CPP
CPP
acos(varr);Parameter: This function takes a mandatory parameter varr which represents valarray. Returns: This function returns a valarray containing the arc cosine of all the elements. Below programs illustrate the above function: Example 1:-
// C++ program to demonstrate
// example of acos() function.
#include <bits/stdc++.h>
using namespace std;
int main()
{
// Initializing valarray
valarray<double>
varr = { 0, 0.25, 0.5, 0.75, 1 };
// Declaring new valarray
valarray<double> varr1;
// use of acos() function
varr1 = acos(varr);
// Displaying new elements value
cout << "The new valarray with"
<< " manipulated values is : "
<< endl;
for (double& x : varr1) {
cout << x << " ";
}
cout << endl;
return 0;
}
Output:
Example 2:-
The new valarray with manipulated values is : 1.5708 1.31812 1.0472 0.722734 0
// C++ program to demonstrate
// example of acos() function.
#include <bits/stdc++.h>
using namespace std;
int main()
{
// Initializing valarray
valarray<double>
varr = { 0.2, 0.14, 5.0, 0.0 };
// Declaring new valarray
valarray<double> varr1;
// use of acos() function
varr1 = acos(varr);
// Displaying new elements value
cout << "The new valarray with"
<< " manipulated values is : "
<< endl;
for (double& x : varr1) {
cout << x << " ";
}
cout << endl;
return 0;
}
Output:
The new valarray with manipulated values is : 1.36944 1.43033 nan 1.5708