Expression differentiation with constants

Question

tmamedzadeh opened this issue 6 years ago · comments

Is it possible to differentiate and expression C*(x+y) by x, showing that C is a constant?

Dream Scatter · Answer 1 · Thu Jul 26 2018 00:38:55 GMT+0800 (China Standard Time)

Do you mean like this?

julia> using Reduce
Reduce (Free CSL version, revision 4590), 11-May-18 ...

julia> Algebra.df( :(c*(x+y)), :x)
:c

note that REDUCE is not set to be case sensitive, so C will be returned as c.

Tarlan Mammadzada · Answer 2 · Thu Jul 26 2018 13:20:51 GMT+0800 (China Standard Time)

How did it recognize that c is constant but y is variable?

Dream Scatter · Answer 3 · Thu Jul 26 2018 13:30:26 GMT+0800 (China Standard Time)

It is treated as partial differentiation, i.e. x is declared as the variable and the others are treated constant.