Lab 8

1. Which of the following function headings are valid? If they are invalid, explain why.
1. one (int a, int b)

2. int thisone (char x)

3. char another (int a, b)

4. double yetanother

2. Consider the following function

int mystery (int x, double y, char ch)

{

int u’

if (‘A’ <= ch && ch <= ‘R’)

return (2*x + static_cast<int> (y));

else

return( static_cast<int>(2 * y) – x);

}

What is the output of the following C++ statements?

a. cout << mystery (5, 4.3, ‘B’) << endl;

b. cout << mystery (4, 9.7, ‘v’_ << endl;

c. cout << 2 * mystery (6, 3.9, ‘D’) << endl;

3. The following formula gives the distance between two points (x₁,y₁) and (x₂,y₂)

If one of the points corresponds to the center point of a circle, and the other point corresponds to a point on the circle, we can figure out the radius of the circle using the above formula.

Here is the main program:

#include<iostream>

#include<cmath>

using namespace std;

//the function prototype goes here

int main()

{

double x1,y1,x2,y2;

cout<<"Enter 4 numbers corresponding to the”;

cout<<"coordinates of two points";

cin>>x1>>y1>>x2>>y2;

cout<<"The radius is: "<<radius(x1,y1,x2,y2);

return 0;

}

//the code of the function goes here

Type in the code that is listed above. Create the function prototype and function code for radius and place them in the appropriate spots. The function accepts 4 double numbers and return 1 double number. The function should use the sqrt and pow predefined functions.

Write another function called circumference, that takes the radius of the circle and returns the circle’s circumference. The formula for a circumference is: 2àr where à = 3.14

Write another function called area that takes the radius of the circle and returns the area of the circle. The formula for the area of the circle is: àr²

Edit main() to call circumference and area and print out the value for both