You are Here: Home >< Maths

# edexcel c2 trig question watch

Announcements
1. please can someone help me with question 7 i have no idea how to do part b
2. (Original post by bigmansouf)
please can someone help me with question 7 i have no idea how to do part b
This is unlike any edexcel question I have ever seen.
If you have found AB then you have you not found the diameter of the circle you are required to find the circumference of?

Posted from TSR Mobile
3. i didnt know if the ball is almost 3/4 in the water or 1/4
the picture is confusing
AB is r but how is it related to the diameter is it a chord?

circumference is 2r but how is related to diameter
4. (Original post by bigmansouf)
i didnt know if the ball is almost 3/4 in the water or 1/4
the picture is confusing
AB is r but how is it related to the diameter is it a chord?

circumference is 2r but how is related to diameter
Are you thinking in 3 dimensions? A ball is a sphere
The ball is floating in water, most of the ball is under the water, only the part above the line AB is above the water.
The picture shows a vertical cross section of the sphere through its centre.
You can calculate the length of the chord AB Using the cosine or sine rule and of the arc AB using theta x r
If you slice off the top of this ball at the level of AB and view it from above, the chord AB is the diameter of the circle you have exposed.

Posted from TSR Mobile
5. thank you very much i want to pick up my GCSE work to relook at 3d dimensions

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: May 17, 2015
Today on TSR

### Update: wrote my dissertation in 48 hours

Find out what mark it got here

### University open days

• Norwich University of the Arts
Thu, 1 Jan '70
• Edge Hill University
Faculty of Health and Social Care Undergraduate
Thu, 1 Jan '70
• Birmingham City University
Thu, 1 Jan '70
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