# the invertibility matrix theorumWatch

#1
I have proved that if the system Ax=b has a unique solution then the system Ax=0 had only the trivial solution. but how do I use the point about the trivial solution to show A is invertible?
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4 months ago
#2
(Original post by aliciacolman1)
I have proved that if the system Ax=b has a unique solution then the system Ax=0 had only the trivial solution. but how do I use the point about the trivial solution to show A is invertible?
Rank-Nullity (if you've done it)?

Note that you will get better responses to maths queries if you go to the forum specifically for discussing maths questions as opposed to university specific stuff: https://thestudentroom.co.uk/forumdisplay.php?f=38
0
#3
thanks I've sorted it now, i did select the option to put it in the university math forum maybe it didn't do it :/
0
4 months ago
#4
(Original post by aliciacolman1)
thanks I've sorted it now, i did select the option to put it in the university math forum maybe it didn't do it :/
To be clear:

There is a forum titled "Mathematics" that is part of the "university" set of forums.
There is a forum titled "Maths" that is part of the "academic help" set of forums - that is the link I gave you.

Historically, "actual maths questions" (as opposed to questions specific to universities, like "I'm at Oxford, can I transfer from physics to maths after one year?") have been posted in the "Maths" forum.

In practical terms, there are a lot more university level posters frequenting the "Maths" forum than the "Mathematics" one, so you'll get better responses asking questions there.

Edit: Unless I've had a brain-fart, you originally posted in the Mathematics forum. It appears someone has now moved your post to the Maths forum for you (helpfully for you, but unhelpfully for me as that happened while I was writing this so I've had to edit!).
Last edited by DFranklin; 4 months ago
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4 months ago
#5
(Original post by DFranklin)
Rank-Nullity (if you've done it)?

Note that you will get better responses to maths queries if you go to the forum specifically for discussing maths questions as opposed to university specific stuff: https://thestudentroom.co.uk/forumdisplay.php?f=38
(Original post by aliciacolman1)
thanks I've sorted it now, i did select the option to put it in the university math forum maybe it didn't do it :/
I've moved this to Maths Study Help now

The University Courses - Mathematics forum is more for discussions about mathematics degrees (applying to them, the course structures and content, options to take and so on). If you need help with problems then they should go in the Maths Study Help forum; although a lot of things posted in there are GCSE/A-level material problems, the study helpers (and others) can help with university level mathematics problems. Quite a few are on maths degrees, or have previously studied one (and at least one person who helps in the forum is a lecturer for a maths course!).

I've also flagged the off-topic comments. You can report any off-topic/non-constructive comments (as well as any offensive comments etc) by clicking "report post" in the top left of the individual comment in the thread and filling in the popup box, if needed.
1
4 months ago
#6
(Original post by DFranklin)
Edit: Unless I've had a brain-fart, you originally posted in the Mathematics forum. It appears someone has now moved your post to the Maths forum for you (helpfully for you, but unhelpfully for me as that happened while I was writing this so I've had to edit!).
That's quite funny really - artful_lounger was just following the confirmed guidance while you were answering

So, aliciacolman1 do you still need any help or are you good to go?
0
#7
I think I'm good now thanks 😁
1
4 months ago
#8
(Original post by aliciacolman1)
I think I'm good now thanks 😁

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