## POLYDER Polynomial Coefficient Differentiation

Section: Optimization and Curve Fitting

### Usage

The `polyder` function returns the polynomial coefficients resulting from differentiation of polynomial `p`. The syntax for its use is either

     pder = polyder(p)

for the derivitave of polynomial p, or

     convp1p2der = polyder(p1,p2)

for the derivitave of polynomial conv(p1,p2), or still

     [nder,dder] = polyder(n,d)

for the derivative of polynomial `n/d` (`nder` is the numerator and `dder` is the denominator). In all cases the polynomial coefficients are assumed to be in decreasing degree. Contributed by Paulo Xavier Candeias under GPL

### Example

Here are some examples of the use of `polyder`

    --> polyder([2,3,4])

    ans =
     4 3

    --> polyder([2,3,4],7)

    ans =
     28 21

    --> [n,d] = polyder([2,3,4],5)
    n =
     -20 -15

    d =
     25