how to derivate a polynomial with x , y and z terms

Using the polynomial for r(t), create a new polynomial for the radial velocity v(t) using the

Matlab polyder() function, which takes a polynomial array as an argument, and returns a

new polynomial array representing the derivative of the initial array

If a have a function r(t)=sqrt( x(t))^2+ y(t))^2+ z(t))^2)

how polyder function would work in this case?

Answer 1

[Torsten]

how polyder function would work in this case?

Your function is not a polynomial ; thus it doesn't work.

"polyder" works on vectors of coefficients of the polynomial. Here is a different way:

syms t
p = [3*t^4+t^2,t^8-3*t^5-22*t];
dp = diff(p,t)

dp =