The Student Room Group
Uni students - Complete our survey >>
Uni students - Complete our survey >>
Uni students - Complete our survey >>

First Differentials

I'm stuck on an FP2 question.
x dy/dx +(1-2x)y = x

I know I need to divide throughout by x to make it a perfect differential so I get (1-2x)/x in front of the y. where do I go from here? If I integrate that bit above e to do the usual steps it goes weird.

Sorry for the weird explanation.
Original post by flyingraccoon
If I integrate that bit above e to do the usual steps it goes weird.

Sorry for the weird explanation.


Yeah, you need to find the integrating factor and multiply through by that.

Why does it go weird? :smile:
Original post by usycool1
Yeah, you need to find the integrating factor and multiply through by that.

Why does it go weird? :smile:


I end up with yx/e^2x =int x/e^2x

I have no clue how to integrate the right hand side and I think it may have gone wrong when trying to find my integrating factor. I did e^int 1-2x/x and ended up with x/e^2x.
Original post by flyingraccoon
I end up with yx/e^2x =int x/e^2x

I have no clue how to integrate the right hand side and I think it may have gone wrong when trying to find my integrating factor. I did e^int 1-2x/x and ended up with x/e^2x.


That looks fine :yy:

You can use by parts to integrate the RHS.
Original post by usycool1
That looks fine :yy:

You can use by parts to integrate the RHS.


I think it works now :smile: thanks
Reply 5
Avatar for Rkai01
Rkai01
6
A bit random but would anyone say dropping M1 for FP2 is stupid as I dislike Mechanics?Also pure modules are helpful for someone like me as Im doing Economics and a lot of Further methods are used I believe whereas I would almost never use any M1 methods in econ.

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you