Differentiate with respect to 'cos(theta)'

Hi, I am trying to differentiate with respect to cos(theta), but I can't seem to get matlab to do this. If I use the diff function I get:

>> diff(cos(the),cos(the))

ans =

diff(cos(the), cos(the))

When the answer I'm looking for is 1. If anyone knows of a way to do this it would be greatly appreciated! Cheers!

Answer 1

[Walter Roberson]

It is easy to get this wrong. Please see http://www.mathworks.com/matlabcentral/answers/40904-how-to-symbolically-differentiate-a-function-with-respect-to-a-different-function