Please write function using Matlab

a) Write a function that, given a vector of values from an unknown func- tion, estimates the derivative at a given point by interpolating a polynomial through the closest 3 available points and differentiating the polynomial ana lytically. (Hint: It might help to use sort.) a) Write a function that, given a vector of values from an unknown func- tion, estimates the derivative at a given point by interpolating a polynomial through the closest 3 available points and differentiating the polynomial ana lytically. (Hint: It might help to use sort.)