togouni2017
Badges: 7
Rep:
? You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#1
Report Thread starter 5 years ago
#1
I got question 9 (d) and (e) incorrect, I've looked at the markscheme but I still don't quite understand the concepts used to work out the center and radius of the circle here. Help?

http://pmt.physicsandmathstutor.com/...%20Edexcel.pdf

Mark Scheme : http://pmt.physicsandmathstutor.com/...%20Edexcel.pdf
0
reply
plaguarist
Badges: 7
Rep:
? You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#2
Report 5 years ago
#2
(Original post by togouni2017)
I got question 9 (d) and (e) incorrect, I've looked at the markscheme but I still don't quite understand the concepts used to work out the center and radius of the circle here. Help?

http://pmt.physicsandmathstutor.com/...%20Edexcel.pdf

Mark Scheme : http://pmt.physicsandmathstutor.com/...%20Edexcel.pdf
My FP1 is Rusty but I think I have it figured.

The points opq are on the circle, and you've proved the angle is pi/2.
There is a circle theorem where a triangle in a circle where all three points touch the circle and contains a right angle must have a line across the diameter. Therefore PQ is a diameter and the centre is simply the average of the x's (The real) and the y's (the complex)

for e) pythagoras gives you a distance which must be the radius as it's from the origin (which from the centre is a radius)
2
reply
togouni2017
Badges: 7
Rep:
? You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#3
Report Thread starter 5 years ago
#3
(Original post by plaguarist)
My FP1 is Rusty but I think I have it figured.

The points opq are on the circle, and you've proved the angle is pi/2.
There is a circle theorem where a triangle in a circle where all three points touch the circle and contains a right angle must have a line across the diameter. Therefore PQ is a diameter and the centre is simply the average of the x's (The real) and the y's (the complex)

for e) pythagoras gives you a distance which must be the radius as it's from the origin (which from the centre is a radius)
damn circle theorems! Been a long time since GCSE Maths last gave me a slap in the face.
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

How did your Edexcel A-level Economics Paper 1 go?

Loved the paper - Feeling positive (72)
16.63%
The paper was reasonable (212)
48.96%
Not feeling great about that exam... (103)
23.79%
It was TERRIBLE (46)
10.62%

Watched Threads

View All