Write a recursive, int-valued function, len, that accepts a string and returns the number of characters in the string.
the length of a string is:
0 if the string is the empty string ("").
1 more than the length of the rest of the string beyond the first character.

Answer the following questions regarding your system by using the commands listed in this chapter. for each question, write the command you used to obtain the answer. a. what are the total number of inodes in the root filesystem? how many are currently utilized? how many are available for use? b. what filesystems are currently mounted on your system? c. what filesystems are available to be mounted on your system? d. what filesystems will be automatically mounted at boot time?

Which factor is the most important when choosing a website host? whether customers will make secure transactions the number of email accounts provided the purpose of the website the quality of the host control panel

Write a program that displays the following menu: geometry calculator 1. calculate the area of a circle 2. calculate the area of a rectangle 3. calculate the area of a triangle 4. quit enter your choice (1-4): if the user enters 1, the program should ask for the radius of the circle and then display its area. use the following formula: area = ď€(the square of r) use 3.14159 for ď€ and the radius of the circle for r. if the user enters 2, the program should ask for the length and width of the rectangle and then display the rectangle’s area. use the following formula: area = length * width if the user enters 3, the program should ask for the length of the triangle’s base and its height, and then display its area. use the following formula: area = base * height * .5 if the user enters 4, the program should end. input validation: display an error message if the user enters a number outside the range of 1 through 4 when selecting an item from the menu. do not accept negative values for the circle’s radius, the rectangle’s length or width, or the triangle’s base or height. note: if the user enters an improper menu choice (1-4), the program prints "the valid choices are 1 through 4. run the program again and select one of those." if the user enters a negative radius, the program prints "the radius can not be less than zero." if the user enters a negative value for height or base, the program prints "only enter positive values for base and height."