Question

Give the function header for each of the following functions: a. Function hypotenuse that takes two double-precision, floating-point arguments, sidel and side2, and returns a double-precision, floating-point result b. Function smallest that takes three integers, \(x, y\) and \(z,\) and returns an integer. c. Function instructions that does not receive any arguments and does not return a value. [Note: Such functions are commonly used to display instructions to a user. d. Function int To bouble that takes an integer argument, number, and returns a doubleprecision, floating-point result.

Short answer

```cpp double hypotenuse(double side1, double side2); int smallest(int x, int y, int z); void instructions(); double intToDouble(int number); ```

Step-by-step solution

Identify the Function Header Format

The standard format for a function header in C++ is `return_type function_name(parameter_type parameter_name, ...);`. We will use this format to construct the headers for each function.

Create Function Header for hypotenuse

The `hypotenuse` function takes two double-precision arguments and returns a double-precision result. Hence, the function header is: ```cpp double hypotenuse(double side1, double side2); ```

Create Function Header for smallest

The `smallest` function takes three integer arguments and returns an integer. Thus, the function header is: ```cpp int smallest(int x, int y, int z); ```

Create Function Header for instructions

The `instructions` function does not receive any arguments and doesn't return any values. This means the return type is `void`, and the header is: ```cpp void instructions(); ```

Create Function Header for intToDouble

The `intToDouble` function takes an integer argument and returns a double-precision result. Thus, the function header is: ```cpp double intToDouble(int number); ```

Key concepts

double-precision arguments

Double-precision arguments in C++ are essentially floating-point numbers that offer a higher degree of accuracy compared to single-precision types. This is due to double-precision floating-point types using more bits to represent the number, allowing for a wider range and greater precision.
When a function in C++ is designed to handle such data, the function's parameters can specifically take these double values. For example, in a scenario where precise calculations are necessary, such as determining the length of a hypotenuse in a triangle, double-precision arguments are ideal.
A double in C++ is declared using the keyword `double`. In a function header, you will see this data type specified for both input parameters and the return type if the output also needs high precision.

• Example function header with double-precision arguments:
  `double calculateArea(double radius);`
• This function takes one double argument and returns a double result, ensuring both input and output are accurate.

integer arguments

Integer arguments in C++ refer to parameters in functions that specifically work with whole numbers. These are numbers without any fractional or decimal component, commonly represented by the `int` data type in C++.
Using integer arguments is efficient for functions that need to handle simple counting, indexing, or arithmetic operations that don’t require precision beyond whole numbers.
For instance, a function that finds the smallest number among a set of integers would use integer arguments. The function can then easily manipulate and perform operations on these numbers.

• Example function header with integer arguments:
  `int findMax(int a, int b, int c);`
• This function takes three integer arguments and returns an integer, indicating the maximum of the three.

void return type

In C++, a function with a `void` return type does not return any value. This is particularly useful for functions whose primary purpose is executing an action or series of actions, rather than calculating and providing a result.
For example, a function might display messages or perform logging actions. These operations do not need to return values because their success or completion isn't measured by any output.
To declare a function with no return value, use the `void` keyword before the function name.

• Example of a function with a void return type:
  `void printInstructions();`
• This function would typically display instructions to a user without returning any data.

function header format

The function header in C++ is the initial line that specifies the function's return type, name, and parameters. This format is crucial as it declares the types of input arguments the function expects, the type of value it returns, and provides the function's signature.
The basic format is as follows:
**`return_type function_name(parameter_type parameter_name, ...);`**
This straightforward structure allows both the programmer and the compiler to understand how the function should be used. It's important to match the return types and parameter types with the actual data the function will handle.

• For a function that returns a double and takes two double arguments:
  `double calculate(double a, double b);`
• For a function with integer parameters returning an integer:
  `int sum (int x, int y);`

This clarity in the function header aids in maintaining consistency and reducing errors in code.