# valarray cos() function in C++

• Last Updated : 08 Mar, 2023

The cos() function is defined in valarray header file. This function is used to calculate cosine of the value of each element in valarray and returns a valarray containing the cosine of all the elements. Syntax:

cos(varr);

Time Complexity: O(1)

Auxiliary Space: O(1)

Parameter: This function takes a mandatory parameter varr which represents valarray. Returns: This function returns a valarray containing the cosine of all the elements. Below programs illustrate the above function: Example 1:-

## CPP

 // C++ program to demonstrate// example of cos() function. #include using namespace std;int main(){    // Initializing valarray    valarray        varr = { 0, 0.25, 0.5, 0.75, 1 };     // Declaring new valarray    valarray varr1;     // use of cos() function    varr1 = cos(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 0.968912 0.877583 0.731689 0.540302

Example 2:-

## CPP

 // C++ program to demonstrate// example of cos() function. #include using namespace std; int main(){    // Initializing valarray    valarray        varr = { 1.2, 3.14, 5.0, 0.0 };     // Declaring new valarray    valarray varr1;     // use of cos() function    varr1 = cos(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 :
0.362358 -0.999999 0.283662 1

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