11-19-2017, 03:39 PM

If there is a lexicon formality, how should equal power terms involving cos() and sin() be displayed in "proper" order?

Here's an example:

y:=cos(x^4)^2;

y'; ==> -2*4*x^3*sin(x^4)*cos(x^4) Notice the factoring order

collect(y'); ==> -8*x^3*cos(x^4)*sin(x^4) The cos() and sin() get reversed here.

(In this case increasing power order): Without any mathematical difference, what, if any, is the proper, or most formal way to express the ordering of the trig terms?

Here's an example:

y:=cos(x^4)^2;

y'; ==> -2*4*x^3*sin(x^4)*cos(x^4) Notice the factoring order

collect(y'); ==> -8*x^3*cos(x^4)*sin(x^4) The cos() and sin() get reversed here.

(In this case increasing power order): Without any mathematical difference, what, if any, is the proper, or most formal way to express the ordering of the trig terms?