2012 Year 9 &10 Mathematics Marathon (2 Viewers)

[kazemagic]

Re: 2012 Year 9 &10 Mathematics Marathon

yes that's right, go try it

na lol i think i forgot how to draw a parabola

 

[twinklegal19]

Re: 2012 Year 9 &10 Mathematics Marathon

na lol i think i forgot how to draw a parabola

you don't even have to draw one in this question just work out the vertex and the intersection algebraically...

 

[kazemagic]

Re: 2012 Year 9 &10 Mathematics Marathon

first one is probably 200
for the 2nd one that ramp line, does it intersect the parabola 2 times?

 

[twinklegal19]

first one is probably 200
for the 2nd one that ramp line, does it intersect the parabola 2 times?

yeah, one of them at (0,0), which isn't what we want so you need to find the other one.

 

[kazemagic]

Re: 2012 Year 9 &10 Mathematics Marathon

for question 2 is it 19.5? it's probably wrong lol

 

[kazemagic]

Re: 2012 Year 9 &10 Mathematics Marathon

did I just kill this thread?

 

[twinklegal19]

Re: 2012 Year 9 &10 Mathematics Marathon

for question 2 is it 19.5? it's probably wrong lol

that's right

did I just kill this thread?

nope,

will post a question soon to revive this thread hehe.

 

[twinklegal19]

Re: 2012 Year 9 &10 Mathematics Marathon

 

[Carrotsticks]

Re: 2012 Year 9 &10 Mathematics Marathon

Haha that's so cute, a 'mushroom ornament'.

 

[Fawun]

Re: 2012 Year 9 &10 Mathematics Marathon

I have a feeling that my answer is incorrect but here is attempt:

I find Latex confusing and time consuming to use so I decided to write it out. Sorry if you can't read my handwriting.

 

[Ealdoon]

Re: 2012 Year 9 &10 Mathematics Marathon

^ You have very neat handwriting.

 

[Carrotsticks]

Re: 2012 Year 9 &10 Mathematics Marathon

^ You have very neat handwriting.

This.

 

[twinklegal19]

Re: 2012 Year 9 &10 Mathematics Marathon

I have a feeling that my answer is incorrect but here is attempt:

I find Latex confusing and time consuming to use so I decided to write it out. Sorry if you can't read my handwriting.

Your solution is right, however the final answer is actually to 3 sig figs, or

try to keep your working in exact form and round off only in the end

otherwise, correct!

also, definitely very nice handwriting

 

[ymcaec]

Re: 2012 Year 9 &10 Mathematics Marathon

Your solution is right, however the final answer is actually to 3 sig figs, or

try to keep your working in exact form and round off only in the end

otherwise, correct!

also, definitely very nice handwriting

actually she forgot to minus the small cone

 

[kazemagic]

Re: 2012 Year 9 &10 Mathematics Marathon

actually she forgot to minus the small cone

lolwut

 

[Demento1]

Re: 2012 Year 9 &10 Mathematics Marathon

actually she forgot to minus the small cone

Well spotted, I was thinking there was something incorrect with that solution based on the final answer.

 

[kazemagic]

Re: 2012 Year 9 &10 Mathematics Marathon

Eliminate theta from the following expressions:

omg lol just saw this question in the 2u jb fitzpatrick book. Page 174 Q.11

I came back wanting to cheat, seems like I can't find the worked solution for this question in this thread :/

 

[Demento1]

Re: 2012 Year 9 &10 Mathematics Marathon

omg lol just saw this question in the 2u jb fitzpatrick book. Page 174 Q.11

I came back wanting to cheat, seems like I can't find the worked solution for this question in this thread :/

If I recall correctly from what Carrot has said, this is the proof you can use to show the equation of an ellipse.

 

[iBibah]

Re: 2012 Year 9 &10 Mathematics Marathon

omg lol just saw this question in the 2u jb fitzpatrick book. Page 174 Q.11

I came back wanting to cheat, seems like I can't find the worked solution for this question in this thread :/

Yeh it's also in Cambridge, quite common actually.

If I recall correctly from what Carrot has said, this is the proof you can use to show the equation of an ellipse.

Correct (though not a 'proof' rather a derivation)

Try with x=cosa and y=sina and you get the unit circle essential to trig.

 

[kazemagic]

Re: 2012 Year 9 &10 Mathematics Marathon

k i got it, had to use trig identity tho :/ don't know how u guys got it without using it