Hey there! Sign in to join this conversationNew here? Join for free
x Turn on thread page Beta
 You are Here: Home >< Maths

# Integration !!! watch

1. Where am I going wrong? thank you
Attached Images
2. Scan0185.pdf (323.3 KB, 58 views)
3. (Original post by otrivine)
Where am I going wrong? thank you
When you substituted u, you forgot to write your integral in terms of u. What you've actually said is

,

which is clearly not correct.

Try a substitution of instead of and post your working if you're still stuck.
4. (Original post by notnek)
When you substituted u, you forgot to write your integral in terms of u. What you've actually said is

,

which is clearly not correct.

Try a substitution of instead of and post your working if you're still stuck.

but its correct cause you use the identity of sin2x=2sinxcosx to get it into that form
5. (Original post by otrivine)
but its correct cause you use the identity of sin2x=2sinxcosx to get it into that form
You're not understanding what I'm getting at.

Notice that from the line

to the line

you have used a substitution but your integral is still in terms of t.

Think about how you normally use a substitution. You normally end up with an integral in terms of u if you use a u substitution right?

This is how your working should read with a substitution :

Notice that there is a du on the RHS which is different to your working. I recommend you don't continue the working from here and use a sub instead.

Reply
Submit reply
Turn on thread page Beta
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: March 18, 2013
Today on TSR

### Loughborough better than Cambridge

Loughborough at number one

Poll
Useful resources

## Make your revision easier

### 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

Can you help? Study help unanswered threads

## Groups associated with this forum:

View associated groups

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

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