## 90 Reputation

2 years, 249 days

## @acer : Thank you a lot!...

@acer : Thank you a lot!

## @dharr : Thank you...

@dharr : Thank you

## @dharr : It's just not tru...

@dharr : It's just not true for powers of 2, is it?

## @Carl Love : Wow! Your counter...

@Carl Love :
Wow! Your counter-example is absolutely correct.

However I solved it like this:

Since matrix B is invertible, there exists its inverse matrix B-  . We have: (A.B-)2023= A2023.(B-)2023=0
deduce: C = A.B-  is nilpotent , so, ==> I- A.B-  invertible. (according to part a).
==> (I- A.B-).B = B-A invertible (because the product of two invertible matrices is invertible).
Please help me point out the error in my argument!
Thank youso much!

## @Carl Love : I solved it. Than...

@Carl Love : I solved it. Thank you again!

## @Carl Love : Could you help me...

@Carl Love : Could you help me further, about part b?

## @Carl Love : Thank you a lot for yo...

@Carl Love : Thank you a lot for your suggestion.

## @vv  I can solve that problem by h...

I can solve that problem by hand, but can't write commands to solve it with Maple.

## @Carl Love  I think they want to t...

I think they want to test skills in manipulating the properties of powers (a^m*a^n=a^(m+n))(?). I myself forgot to use this feature at first, so I encountered difficulty in solving problems.

## @Carl Love  Thank you very much! W...

Thank you very much! With your suggestion, I solved the problem (by hand).

## @Carl Love  It's amazing how a...

It's amazing how a seemingly complicated problem can be solved so simply! Thank you so much for your help!

## @Kitonum  Sorry! If the bound of t...

Sorry! If the bound of the integral is 1..2 (int(x*f(x), x=1..2) then I really have a trick to solve it quickly without using Maple (using a constant function). Issue is here that I don't dare to assert that the requirement to compute primitives with bounds of 2..3 is not satisfactory. Thank you again.

## @Kitonum  Thank you very much!&nbs...

Thank you very much! I also thought there was a problem with the assumptions of the problem (the bounds of the integrals are not equivalent). But because my level of math is limited, I dare not boldly assert.

## @rlopez Great! Thank you very much!...

Great! Thank you very much! Although I understand the problem you have explained, but due to skill limitation, I am not able to write the complete statement of command. Can you help me, for this particular case? Sorry if I have bothered. Thank you very much!

## @vv  Thank you! Now I understood!&...

Thank you! Now I understood!

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