$($Sides of a Right Triangle$)$ Write an application that reads three nonzero integers and determines and prints whether they could represent the sides of a right triangle.

$$

$4\mathrm{.}38($Factorial$)$ The factorial of a nonnegative integer n is written as n$!($pronounced $$n factorial$)$ and is defined for values of n greater than or equal to $1$ as:

and for the n value $0$ as:

For example,

$$which is $120.$

$$

Write an application that reads a nonnegative integer and computes and prints its factorial.

$$

Write an application that estimates the value of the mathematical constant e by using the following formula. Allow the user to enter the number of terms to calculate.

Write an application that computes the value of

$$by using the following formula. Allow the user to enter the number of terms to calculate.

$$