Extension One Revising Game (2 Viewers)

[addikaye03]

Oh shit.
Is it because sin(180 - theta) = sin(theta)?
So theta can be 74'37' OR 105'22'?

P.S. You're a genius Trebla

But, if u went ahead and found angle ACB the 105 degree one wouldn't be allowed, due to the 180 degree restriction. I think im missing something..

EDIT: i see now... i am an idiot! Anyone had any luck on my previous Q

 

[Timothy.Siu]

But, if u went ahead and found angle ACB the 105 degree one wouldn't be allowed, due to the 180 degree restriction. I think im missing something..

why?
ones 105, and the others 40,

 

[addikaye03]

why?
ones 105, and the others 40,

yer ino, i editted it, adding im an idiot lol i dont know what i was thinking..

 

[Trebla]

My Year 11 teacher always said that whenever you use the sine rule, watch out for the ambiguous case...lol.

However, in this case the other answer is possible, because the angle is small enough to be feasible.

In most simple cases, the other angle is too large such that the sum of two angles already exceeds 180 degrees.

 

[addikaye03]

My Year 11 teacher always said that whenever you use the sine rule, watch out for the ambiguous case...lol.

However, in this case the other answer is possible, because the angle is small enough to be feasible.

In most simple cases, the other angle is too large such that the sum of two angles already exceeds 180 degrees.

Yer thanks, I did watch for that but for some reason i left angle ACB as 65 degrees and thought well its not possible then as it exceeds 180 degrees. For some reason i didnt realise that angle ACB variated due to angle ABC. Sorry bout the stupid confusion everyone lol

 

[addikaye03]

My previous Q still not answered..

 

[bored of sc]

Question: Prove by mathematical induction, the sum of the exterior angles of a n-sided polygon=360 degrees

(1) n = 1, x = sum of exterior angles, s = sum of interior angles = (n-2)180
x+s = 180n
x = 180n-s
x = 180*1-(1-2)180
= 180+180
= 360
So true for n = 1

(2) Assume true for n = k
180k-(k-2)180 = 360

(3) Prove true for n = k+1
x = 180(k+1)-(k+1-2)180
= 180k+180-180k-180+360
= [360+(k-2)180]+180-180k-180+360 --- using assumption
= 360+180k-360+180-180k-180+360
= 360

It is true for n = K+1 if true for n = k. Since it is true for n = 1 it is true for n = 1+1 = 2, n = 3 etc and hence all integer n > 0.


Is that right?

 

[lyounamu]

(1) n = 1, x = sum of exterior angles, s = sum of interior angles = (n-2)180
x+s = 180n
x = 180n-s
x = 180*1-(1-2)180
= 180+180
= 360
So true for n = 1

(2) Assume true for n = k
180k-(k-2)180 = 360

(3) Prove true for n = k+1
x = 180(k+1)-(k+1-2)180
= 180k+180-180k-180+360
= [360+(k-2)180]+180-180k-180+360 --- using assumption
= 360+180k-360+180-180k-180+360
= 360

It is true for n = K+1 if true for n = k. Since it is true for n = 1 it is true for n = 1+1 = 2, n = 3 etc and hence all integer n > 0.


Is that right?

That's very good.

 

[bored of sc]

That's very good.

So are you sure it's correct?

 

[lyounamu]

So are you sure it's correct?

but there are some flaws...you sure n=1? because you cannot use n=1 or n=2

so you should alter n=1 thing-o. start with n=3 and n>=3 always

 

[bored of sc]

but there are some flaws...you sure n=1? because you cannot use n=1 or n=2

so you should alter n=1 thing-o. start with n=3 and n>=3 always

Oh yeah, start with a triangle.

 

[Trebla]

A possible solution is in the syllabus: (p49)
http://www.boardofstudies.nsw.edu.au/syllabus_hsc/pdf_doc/maths23u_syl.pdf

 

[addikaye03]

A possible solution is in the syllabus: (p49)
http://www.boardofstudies.nsw.edu.au/syllabus_hsc/pdf_doc/maths23u_syl.pdf

The solution i had was basically what was on this page. And a polygon is a minimum of three sides as mentioned.

Thats a pretty cool Q i think ftw!

 

[addikaye03]

Anyone got anymore q?

 

[Timothy.Siu]

Anyone got anymore q?

do mine please

All the letters of the word ENCUMBRANCE are arranged in a line. Find the total number of arrangements, which contain all the vowels in alphabetical order but separated by at least one consonant.

 

[addikaye03]

i got 41580 ways but i dont think. that is right..its quite an unusual Q aye. U got any idea yet?

 

[Trebla]

I had a go at it (posted working on the thread created by Timothy.Siu) and got 7560. I have a lot of doubts around that number though.
One thing I can say without doubt is that it's very horrible. lol

 

[addikaye03]

I had a go at it (posted working on the thread created by Timothy.Siu) and got 7560. I have a lot of doubts around that number though.
One thing I can say without doubt is that it's very horrible. lol

Ur solution is amazing. I dont know if its right.. but i understand it. Well done anyway lol

 

[Timothy.Siu]

Ur solution is amazing. I dont know if its right.. but i understand it. Well done anyway lol

i've asked a few people and the answers i get range from 100k-500k....but now even less lol

 

[Aerath]

i've asked a few people and the answers i get range from 100k-500k....but now even less lol

Hmmm, so where did my answer of: "Fuck off, don't ask me perms and combs questions" fit in?