The first and second derivatives of a function $f(x)$ can be approximated by computing the finite difference between neighboring points, e$.$g$.f(x+-h)$ and $f(x+-2h).$ The following expressions are constructed to approximate the derivatives. Complete the construction by determining the constants $A,B,C,D,E$ and n $.$

$($a$)h{f}^{\text{'}}(x)=Af(x+2h)+Bf(x+h)+Cf(x)+Df(x-h)+O(h^{n+1})$

$($b$)h^2{f}^{\text{'}\text{'}}(x)=Af(x+2h)+Bf(x+h)+Cf(x)+Df(x-h)+Ef(x-2h)+O(h^{n+2})$