Partial differentiation-Multiple syms derivative x and y

I have a eq. like this y=cosh(L*x)*cos(L*y) (1)

What is the code that I must do if I want to have a result like this: y'=L*x'*sinh(L*x)*cos(L*y)-L*y'*sin(L*y)*cosh(L*x) (2)

I just need a eq.2. I don't know how to call the caculation from 1-2. Sorry about it. Thanks in advance.

Answer 1

[Torsten]

syms  t, L

x = sym('x(t)'); % x(t)
y = sym('y(t)'); % y(t)

E1 = diff(y);

E2 = cosh(L*x)*cos(L*y);

E3 = diff(E2,t);

pretty(E1)

pretty(E3)

Best wíshes

Torsten.

[vu ngothanh]

Dear Mr. Torsten, Why you put E1 in your code. I don't understand about it. If I remove it, it still give a same result. Thank you

Answer 2

[Torsten]

http://www.mathworks.com/matlabcentral/answers/94623-how-do-i-symbolically-work-with-implicit-functions-i-e-x-t-within-the-symbolic-math-toolbox

Best wishes

Torsten.

Answer 3

[vu ngothanh]

Thank you for your help. But, your link just solved the diff of x, while I need diff in both x and y. Can you help me again. Thanks a lot

Answer 4

[vu ngothanh]

Thanks you very much.