C++ Language please

Write a program that contains the following functions, i. A function isVowel that takes in a character and returns true if it is a vowel and false otherwise ii. A function that request from the user to enter in a sequence of characters, and outputs the number of vowels entered. (Use Function in a) to assist you, a sentinel value can be used to specify the end of the user input iii. A function that reads 3 test scores from 5 different students stored in a file and returns the highest average test score