a) Here is a line of code: sum= a+b

write a complete C function named fun that has a and b as parameters and returns their calculated sum via the return statement.Assume all the values are integers.

........

roblem tl4 un point) Here is a line of code: sum a b; write a complete C function named fun that has a and b as parameters and returns their calculated sum via the return statement, Assume all the values are integers. b) What is the purpose of a function prototype? When is a prototype NOT needed in a program? c) Suppose the function fun is also expected to compute the difference (a b) and the product (a b). Re-write your function so that it can send all three values diff, prod) back. Do not use a structure. (sum, d) suppose you have e following code fragment: int x, y; print ("Enter two integers: scanf ("Xd %d", &x, &y); Your function call to fun goes after this line write the code needed to invoke (call) your function. Pass itthe x and y values. Also declare any other variables you need to hold the values that the function nds back. se