You are Here: Home >< Maths

differentials watch

Announcements
1. how do I work out y" + 6y' + 10y = 20, when it doesn't completely factorise when I use the factorisation method?
2. If it doesn't factorize, use the quadratic formula (or complete the square) instead...
3. (Original post by Kolya)
If it doesn't factorize, use the quadratic formula (or complete the square) instead...
that gets -3 + i, -3 - i as solutions. then I've been told sin and cos appear in the final solution...

4. That's what wolfram gives.
5. Check this post out

http://www.thestudentroom.co.uk/show....php?t=1169201

all the answers you need here
6. (Original post by MikeL230)

That's what wolfram gives.
yes, but HOW do you get that?
Check this post out

http://www.thestudentroom.co.uk/show....php?t=1169201

all the answers you need here
doesn't help either
8. If you get p +/- iq as solutions to the quadratic (for real numbers p and q), then your complementary solution will always be

for some real numbers A and B.

If you want a cheat proof for "WHY?!!?!?!", then just sub that into your differential equation and watch it come out to 0. If you want a proper proof, look it up on Google.
9. never mind, got help from someone else.

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:
Updated: January 31, 2010
Today on TSR

Uni league tables

Do they actually matter?

University open days

• University of Warwick
Sat, 20 Oct '18
• University of Sheffield
Sat, 20 Oct '18
• Edge Hill University
Faculty of Health and Social Care Undergraduate
Sat, 20 Oct '18
Poll
Useful resources

Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

How to use LaTex

Writing equations the easy way

Study habits of A* students

Top tips from students who have already aced their exams

Chat with other maths applicants