Error with taylor series expansion

Hi,

I was trying to compute the Taylor series approximation of a function as follows:

clc
clearvars
syms Theta(t) Phi(t) r
x = r/ sqrt(1 + tan(Theta)^2 + tan(Phi)^2)
xt = taylor(x, [Theta(t) Phi(t)])

This gives me the following error

Error using sym/taylor (line 99)
The value of 'x' is invalid. It must satisfy the function: @(x)isvector(x)&&isAllVars(x).

However this works removing the dependency of Theta and Phi from t as follows

syms Theta Phi r

Any idea?

Thanks

[LU kelon]

Have you solved this problem?I have trouble too

Answer 1

[Walter Roberson]

The second input to taylor must evaluate to a scalar symbolic variable . You cannot taylor with respect to two items at the same time and you xannot taylor with respect to a function .