How to calculate detivative of a function with respect to another function

Hi! I want to calculate the derivative below in matlab

Have anyone any idea?

Answer 1

[madhan ravi]

syms u x
subs(diff(u^2 - 1), u, cos(x))

[Laura Passalacqua]

Thanks a lot!

Answer 2

[Alan Stevens]

Surely you don't need to do this in Matlab!

Just set u = cos(x), so you have d/du(u^2 - 1) = 2u = 2cos(x)