x Turn on thread page Beta
 You are Here: Home >< Maths

# C4 PPQ June 2008 watch

1. Hey.
https://983c9f06eb1f75af6e83364e092b...20C4%20OCR.pdf
Could somone explain question 9 (i) to be i was able to the a theta value for a by using the fact that DY/DX=0 as its a turning point but i dont see what to use for B.
Thanks
2. (Original post by SamuelN98)
Hey.
https://983c9f06eb1f75af6e83364e092b...20C4%20OCR.pdf
Could somone explain question 9 (i) to be i was able to the a theta value for a by using the fact that DY/DX=0 as its a turning point but i dont see what to use for B.
Thanks
At B, y = 0.

For A you don't need dy/dx, just use the fact that y is maximum at A and consider .
3. (Original post by notnek)
At B, y = 0.

For A you don't need dy/dx, just use the fact that y is maximum at A and consider .
For B how do i determine which value of theta that makes sine(theta)=0 to use.
0, or 2 ?
4. (Original post by SamuelN98)
For B how do i determine which value of theta that makes sine(theta)=0 to use.
0,pie or 2 pie?
Well, you know it can't be 0 since that would make x be 0 as well. Now can you justify what it is between pi and 2pi using the position of A?
5. (Original post by SamuelN98)
For B how do i determine which value of theta that makes sine(theta)=0 to use.
0,pie or 2 pie?
Plug these values of into then determine which one of these coordinates must be B.

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: April 21, 2016
Today on TSR

### Loughborough better than Cambridge

Loughborough at number one

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