# Differential Equation (exam tomorrow!)

Announcements Posted on
TSR's new app is coming! Sign up here to try it first >> 17-10-2016
1. Hey guys I can't solve this first order DE

(2e^y - x ) *dy/dx = 1

Im not sure what method to use and got really confused. Any help appreciated!
2. 1. Define a new variable v=e^y and rewrite the equation in terms of dv/dx.
2. Define another new variable u=v/x and rewrite the dv/dx equation in terms du/dx. You should get a separable ODE.
3. Solve for u(x) then substitute back its value in terms of y and make y the subject of the equation. (May have to use exponentiation and the quadratic equation)

## Register

Thanks for posting! You just need to create an account in order to submit the post
1. this can't be left blank
2. this can't be left blank
3. this can't be left blank

6 characters or longer with both numbers and letters is safer

4. this can't be left empty
1. Oops, you need to agree to our Ts&Cs to register

Updated: October 11, 2016
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Today on TSR

### How does exam reform affect you?

From GCSE to A level, it's all changing

### Who would you like to thank?

Poll
Study resources

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.