is it really that bad to prove from both sides? (1 Viewer)

[maxxxxx]

i know it would usually be better to prove from lhs to rhs or vice verse but sometimes it is just so much simpler to work on both simultaneously. is it that bad to meet in the middle?

 

[Average Boreduser]

i know it would usually be better to prove from lhs to rhs or vice verse but sometimes it is just so much simpler to work on both simultaneously. is it that bad to meet in the middle?

hsc irrc its adequate but in formal maths its a bit of an ew

 

[liamkk112]

i know it would usually be better to prove from lhs to rhs or vice verse but sometimes it is just so much simpler to work on both simultaneously. is it that bad to meet in the middle?

its not a bad thing to do some sketch work and work from the middle there as it can get u ahead sometimes. but when writing the final proof i would write from lhs to rhs or vice versa

 

[iloveeggs]

i know it would usually be better to prove from lhs to rhs or vice verse but sometimes it is just so much simpler to work on both simultaneously. is it that bad to meet in the middle?

imo no, as long as you can prove rhs=lhs you should get the marks unless the question specifically says do it lhs to rhs or vice versa. and how does it matter if its bad or not impressive if you get the marks?

 

[Average Boreduser]

imo no, as long as you can prove rhs=lhs you should get the marks unless the question specifically says do it lhs to rhs or vice versa. and how does it matter if its bad or not impressive if you get the marks?

Euclid's common notion 1:
Things which equal the same thing also equal one another.
it's perfectly fine to do so, but leaves 10x as much room for error and also may aid less conceptual understanding and more relying on manipulating and hoping it might fit. It's like essentially half assing one side and the other the same way. It doesn't flow yk?

 

[iloveeggs]

Euclid's common notion 1:
Things which equal the same thing also equal one another.
it's perfectly fine to do so, but leaves 10x as much room for error and also may aid less conceptual understanding and more relying on manipulating and hoping it might fit. It's like essentially half assing one side and the other the same way. It doesn't flow yk?

oh yes agreed. you shouldn't be doing this for all of your questions btw just anything you're truly struggling with and the only way you can find to do it on your own is proving from both sides. otherwise if this is your whole technique you're missing the point of the question which is likely gettign you to apply theorems/concepts that help your understanding

 

[K2Trappy]

i know it would usually be better to prove from lhs to rhs or vice verse but sometimes it is just so much simpler to work on both simultaneously. is it that bad to meet in the middle?

Technically the working out wouldn't really make sense cause like if ur writing lhs=rhs and doing things to both to show they're equal ur kinda starting from the assumption that they're equal and ur writing they are equal in everyline even though u haven't proved it, so idk its kinda looks odd that someone asked u to show its equal and u start with it being equal

 

[maxxxxx]

Technically the working out wouldn't really make sense cause like if ur writing lhs=rhs and doing things to both to show they're equal ur kinda starting from the assumption that they're equal and ur writing they are equal in everyline even though u haven't proved it, so idk its kinda looks odd that someone asked u to show its equal and u start with it being equal

That’s not what I’m asking. What I’m saying is that taking the left-hand side and simplifying it to a certain extent; and then taking the right hand side and either simplifying or expanding it to the same extent. Not equating two sides, simply taking both of them and reducing them down to a certain point rather than taking either the left or the right and manipulating to equal.
For example, if I have a very complicated polynomial on either side of a proof question instead of performing simplifications are expansions to one side to make it equal to the other which in some cases is very complex and takes a lot of working. Is it permissible to take left-hand side down to a mid ground and right hand side down to a mid ground.

 

[ss2000]

Technically yes . Given (a=c, b=d, c=d ), then a=b. (extending transitive property).