Please solve this numerical analysis problem

Derive an order h accurate one-sided finite difference approximation to the first derivative do dx at the point x = 27. Suppose that the numerical solution is available at the set of points {} and assume constant grid spacing, i.e. h = Xi+1 - ; is the same for all i. The derivative must be calculated using ; and only points to its left (i.e. Cj, j-1, Cj-2, . . . use as many as you need). Hint: assume that aid; + azo;-1 + a30j-2+ ... h is the numerical approximation to do /dx and calculate the appropriate ai