How to solve all of this question?

c. Write a complete program that has ONE (1) user-defined function. This function will apply pass by reference AND / OR pass by value, to calculate and display the value of y. Given formula y - (x * x + 4). (6 marks) d. Write the definition of the following functions i- ii below: iii. void User Input (int num[], int size) This function asks FOUR (4) integer numbers from user and store the numbers in the array num). (3 marks) iv. int SumPowerTwo (int num[], int size) This function displays the square of every even number in array num[] and returns the sum of all numbers in num[]. Use built-in function to get the square of numbers