Write a user-defined function with function all val = f_eval(f, a, b) where (f) is an anonymous function, and (a) and (b) are constants such that (a < b). The function calculates the midpoint (m) of the interval.
a. all_val = (f(a) + f(b)) / 2
b. all_val = (f(a) f(b)) / 2
c. all_val = (f(a) + f(b)) 2
d. all_val = (f(a) f(b)) 2