The attached problem is from a 1988 MO. It can be solved using complete induction, paper, and pencil, and with some effort, yields a simple answer. It's quite challenging to do by hand, but with "derive", it only takes three lines and a fraction of a second. Mow test.mw

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I can't do it with Maple because I'm doing something wrong again. Therefore, I'm asking for help.

When calculating limits of real-valued functions, sometimes (especially in competitions) tricky approaches are taken using pen and paper. I repeatedly encountered the simple conclusion that, for example, for natural k, the value sin(k*pi) = 0. Thus, the function value is determined logically without specifying a specific number. There are numerous other examples of this that can easily be constructed.
My question after unsuccessful attempts using "assume" is:
How, for example, does Maple determine the value of sin(k*pi) from the assumption "k is natural" alone? Are such prominent values ​​implemented in tables?

In the attached file, I want to restrict the indices of the summation to gcd(m,n)=1. How does this work?

test.mw

In the attached file, I was unable to calculate the limit values ​​L and M. Please help me.

test.mw

In the attached file, I'm trying to calculate a limit. After a long calculation, I've given up. I'm asking for advice on how to perform the calculation effectively in Maple. I know the solution using the pen and paper method (pi/4+1/2*ln(2)).

test.mw