Currently, when I have solution to an ode, say y(x)=sin(x)+_C1 and have some initial condition, then to solve for _C1,  I manually substitute the solution into the IC and replace each x by x0 and replace each derivative manually and so on.

This is because I could not find automatic way to do this. Using another software, it is possible to automate this by writing the solution using the  y -> Function[{x}, ...] syntax. But in Maple, I was not sure how to do the same.

Here is a simple made up example. 

sol:= y(x) = sin(x)+_C1;
IC := a*D(y)(x0)+c*y(x0)= b*y0+exp((D@@2)(y)(x0));

The goal is to replace the solution (which is function y(x)) into the IC, and automatically replace all its derivatives and replace x by x0 then solve for _C1 from the equation that results.

Now I do this manually like this

eval(IC,[ y(x0)=eval(rhs(sol),x=x0), 
          D(y)(x0)=eval(diff(rhs(sol),x),x=x0), 
         (D@@2)(y)(x0)= eval(diff(rhs(sol),x$2),x=x0) ])

which gives

But this is too much work.

Using the other software, I can do the above much more easily like this

sol = y -> Function[{x}, Sin[x] + C[1]]
ic = a*y'[x0] + c*y[x0] == b*y0 + Exp[y''[x0]];
ic /. sol

I looked at algsubs, dchange, or making the solution as function instead, and so on but could not emulate the y -> Function[{x}, Sin[x] + C[1]] method in Maple.

What would be similar method in Maple to do the above automatically?  May be there is already builtin function in Maple?

is it possible to collect using pattern? For example, given 

How to tell Maple to collect on  r^power terms to produce

This came up in another forum here  and using that other software, it is possible to ask collect to collect on pattern r^_

Is there a way in Maple to collect on all powers of r in the above? Here is worksheet

Download collect_using_pattern.mw

Using that other software:

I do not remember if this came up before. And this is all done in code, without looking at the screen.

Given sqrt(1-cos(x)^2), Maple's simplify does not return sqrt(sin(x)^2), instead it returns ugly result csgn(sin(x))*sin(x) which is correct ofcourse, but why not just return sqrt(sin(x)^2)?  As sqrt(sin(x)^2) is much easier to read than csgn(sin(x))*sin(x).

length of sqrt(1-cos(x)^2) is 29 and length of sqrt(sin(x)^2) is 21.

What Maple simplify seems to do is simplify sqrt(1-cos(x)^2) to sqrt(sin(x)^2) internally, but instead of stopping there, it keeps going and "simplifies" sqrt(sin(x)^2)  to csgn(sin(x))*sin(x).

How to make it stop at sqrt(sin(x)^2)?

Again, this is done in code. Not interactive. code uses simplify() command on most things. 

Download simplify_dec_3_2025.mw

That other system does it better

Is it possible to make simplify do the same in Maple? 

DO not know if this is new in Maple 2025.2 or not as I have not looked yet if it is possible to install Maple 2025.1 on my new PC given Maple 2025.2 is already installed.

Found That Maple 2025.2 gives "Error, (in dsolve) numeric exception: division by zero" when asked to solve this ode using Lie symmetry.  The error comes when it tried to 

                        Computing canonical coordinates for the symmetry 

Even if this problem was in earlier Maple versions, this ofcourse should not happen.

Download division_by_zero_dsolve_maple_2025_2_on_dec_2_2025.mw

I have an expression with y,y',y''. I found that I had to use collect first to make Maple simplifies it more.

Why is that? Is this expected?

Download why_collect_is_needed_to_simplify_more_maple_2025_2_nov_30_2025.mw

Notice how much simpler the result when doing collect first.