Question

Write a complete \(\mathrm{C}++\) program to compute and output the square root of \(\mathrm{PI}\) PI is approximately \(3.14159 .\) The const double PI is predefined in cmath. You are encouraged to use this predefined constant.

Short answer

Question: Write a complete C++ program to compute and output the square root of PI, using the cmath library. Answer: ```cpp #include #include int main() { double sqrt_PI = sqrt(M_PI); std::cout << "The square root of PI is: " << sqrt_PI << std::endl; return 0; } ```

Step-by-step solution

Include necessary libraries

Begin by including the necessary libraries, in our case, the iostream library for basic input and output operations and the cmath library to access the PI constant and sqrt() function: ```cpp #include #include ```

Declare main function

Now, declare the main function. The main function is where our program starts execution: ```cpp int main() { ```

Compute the square root of PI

Inside the main function, compute the square root of PI using the sqrt() function provided by cmath and store it in a double variable: ```cpp double sqrt_PI = sqrt(M_PI); ```

Output the result

Now, output the computed square root of PI using the std::cout stream: ```cpp std::cout << "The square root of PI is: " << sqrt_PI << std::endl; ```

Close the main function

Finally, close the main function by returning 0 to indicate successful execution: ```cpp return 0; } ```

Complete Program

Here is the complete C++ program to compute and output the square root of PI: ```cpp #include #include int main() { double sqrt_PI = sqrt(M_PI); std::cout << "The square root of PI is: " << sqrt_PI << std::endl; return 0; } ```