# Hard question, Need Help!!!Watch

#1
The chord AB of a circle divides the circle into two portions whose areas are in the ratio 3:1. If AB makes an angle θ with the diameter passing through A, show that θ satisfies the equation;

Sin(2θ)= π/2 -2θ

I ended up getting Sin (
θ) = θ - π/2 , from the minor segment ratio but I dont know where to go from here...
0
4 years ago
#2
(Original post by Tiri)
The chord AB of a circle divides the circle into two portions whose areas are in the ratio 3:1. If AB makes an angle θ with the diameter passing through A, show that θ satisfies the equation;

Sin(2θ)= π/2 -2θ

I ended up getting Sin (
θ) = θ - π/2 , from the minor segment ratio but I dont know where to go from here...
I suggest posting your working, as that can't be correct. Your equation has no solution in the interval 0 to pi/2, which is the valid range of theta.
#3

As you can see i posted a picture of the question, its from 1966

Posted from TSR Mobile
0
4 years ago
#4
(Original post by Tiri)

As you can see i posted a picture of the question, its from 1966
Very nice, but I can't see your working. Can't tell where you've gone wrong without that.
4 years ago
#5
(Original post by Tiri)
The chord AB of a circle divides the circle into two portions whose areas are in the ratio 3:1. If AB makes an angle θ with the diameter passing through A, show that θ satisfies the equation;

Sin(2θ)= π/2 -2θ[COLOR=#252525][FONT=Nimbus Roman No9 L]

Nice question
0
4 years ago
#6
I agree, had a lot of fun solving this one and watching everything cancel down really nicely. It's a shame these types of questions rarely appear in any of the exam papers.
2
4 years ago
#7
(Original post by Malgorithm)
It's a shame these types of questions rarely appear in any of the exam papers.
My thoughts exactly
0
#8

Are you lot all pretending that you actually done the question or are you gonna show how you did it? Something doesnt look right

Posted from TSR Mobile
0
4 years ago
#9
(Original post by Tiri)

Are you lot all pretending that you actually done the question or are you gonna show how you did it? Something doesnt look right

Posted from TSR Mobile
The question says that the angle theta is between the diameter and AB. You seem to have labelled it as the angle between OA and OB.

If you just fix that, your method seems to be just fine, it's just the values need altering a bit because you chose the wrong angle for theta.
0
#10
am i being an idiot or is there still something ive missed?

Posted from TSR Mobile
1
4 years ago
#11
(Original post by Tiri)
am i being an idiot or is there still something ive missed?

Posted from TSR Mobile
The angle between AB and the diameter is theta
0
#12
LOL you both are telling me differnt things... How about someone posts solutions if youve done it.. I seem to be stuck on the last little, I cant prove its pie/2 minus theta, only pie minus 2theta.
0
4 years ago
#13
(Original post by Tiri)
LOL you both are telling me differnt things... How about someone posts solutions if youve done it.. I seem to be stuck on the last little, I cant prove its pie/2 minus theta, only pie minus 2theta.
No

We have both told you the same thing

The question states that the angle theta is between AB and the Diameter at A

You are not stuck on the last bit - you have not yet drawn the correct diagram so you do not have the correct angle at the centre
0
#14
done it..

Posted from TSR Mobile
1
4 years ago
#15
(Original post by Tiri)
done it..
good
0
X

new posts
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

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

### University open days

• Cranfield University
Cranfield Forensic MSc Programme Open Day Postgraduate
Thu, 25 Apr '19
• University of the Arts London
Open day: MA Footwear and MA Fashion Artefact Postgraduate
Thu, 25 Apr '19
• Cardiff Metropolitan University
Sat, 27 Apr '19

### Poll

Join the discussion

#### Have you registered to vote?

Yes! (443)
37.86%
No - but I will (88)
7.52%
No - I don't want to (80)
6.84%
No - I can't vote (<18, not in UK, etc) (559)
47.78%