Quick Answers To Some Questions! (1 Viewer)

[gaaay]

Q.8. iv) looks like two boobs hanging down

hahhahaha your hilarious!
but i got that too

 

[smozdaddy]

i agree with this if you were to use geometric term formula you would need to make a = 60 as it is the first zoom then its as simple as applying it to the formula lol i was the only one in my school who did this so i got a bit worried hopefully 120

or just make it Tn=ar^n (where a=50) rather than Tn=ar^(n-1). Both work.

But yeah, i agree with 215mm and 12. Bit of a trick.

 

[velzee]

4b i- 179
ii- n=13

4c
i (0,3)
ii (0,5)
iv 10.5 units^2

5b ii 19/40

6a x= pie/4, x=-pie/4 (im not to sure about this one)
b)i 20
ii 10
iii 6

 

[m.incognito]

Yeah I used the geometric too. But my a was 50. Because 60 is 1.2 times 50.
So really as is 50.

50 x 1.2 ^(8-1)

The answer was 179 to the nearest mm

For part two:

50 x 1.2 ^(13-1) gives 445

whereas

50 x 1.2 ^(12-1) gives 371.5

So n = 13 times

Sorry to be a cow, Priti but lolitoldyouso.

Nah 1st zoom in = 60.
50 was the original value

 

[lazyfrank]

it says 'After the zoom function is applied once, the height is applied once, the height of the building in the image is 60mm.' '..after the zoom function has been applied 8 times?' and 'The height of the building in the image is required to be more than 400. Starting from the original image, what is the least number of times the zoom function must be applied?' it says 1st one is 60 lol

 

[Lovell]

it's 215mm and n=12

Its not n =12 did u test cause i sure did and 12 came up below teh required. its 13.

 

[m.incognito]

4b i- 179
ii- n=13

4c
i (0,3)
ii (0,5)
iv 10.5 units^2

5b ii 19/40

6a x= pie/4, x=-pie/4 (im not to sure about this one)
b)i 20
ii 10
iii 6

6a is incorrect.
2sin^2(x/3) = 1

sin^2(x/3) = 1/2
sin(x/3) = +-1/rt2

x/3 = pi/4 OR -pi/4

.:. x = 3pi/4 OR -3pi/4

 

[smozdaddy]

Yeah I used the geometric too. But my a was 50. Because 60 is 1.2 times 50.
So really as is 50.

50 x 1.2 ^(8-1)

The answer was 179 to the nearest mm

This is for 7 zooms.

it is stated that after beein zoomed once the building appears 60 mm tall.
Hence 50 x (1.2)^1=60.

Similarly 50 x (1.2)^2 = 72.

And using your calculator 50 x (1.2)^8=215mm

For part two:

50 x 1.2 ^(13-1) gives 445

whereas

50 x 1.2 ^(12-1) gives 371.5

So n = 13 times

Basically, the formula is Tn=50(1.2)^n rather than 50(1.2)^(n-1), and so it is actually 12 times.

 

[smozdaddy]

If you use Tn=ar^(n-1) than you end up with the first zoom being 50(when it is stated that it is 60), the second being 60(Its stated its 72) and so on...

 

[velzee]

damn that was my initial answer for 6a then i was an idiot and went back and changed it, arggh

does anybody have the answer for 6b iv?

 

[ywontuend]

This is for 7 zooms.

it is stated that after beein zoomed once the building appears 60 mm tall.
Hence 50 x (1.2)^1=60.

Similarly 50 x (1.2)^2 = 72.

And using your calculator 50 x (1.2)^8=215mm



Basically, the formula is Tn=50(1.2)^n rather than 50(1.2)^(n-1), and so it is actually 12 times.

i agree it was 215mm and 12 times, the first term had no zoom ins so it was with 60 that u started....it was a bit tricky..

 

[Rampager]

50 x 1.2 = 60 (first application)
60 x 1.2 = 72 (second application)
72 x 1.2 = 86.4 (third)
86.4 x 1.2 = 103.68 (fourth)
103.68 x 1.2 = 124.416 (fifth)
124.416 x 1.2 = 149.2992 (sixth)
149.2992 x 1.2 = 179.159 (seventh)
179.159 x 1.2 = 214.49 (eighth)

continuing on...

214.49 x 1.2 = 257 (ninth)
257 x 1.2 = 308.86 (tenth)
308 x 1.2 = 370 (eleventh)
370 x 1.2 = 444 (twelfth)

 

[pyjamapants]

Naw.
Shit. I get you.
Hah. I effed it. And by "it" I mean the whole exam.
Oh well. There's always 3 unit.
I'm gonna go hang myself now.

Edit: Thanks to the beauty of transcription errors I'll probs still get 3/4
hah.
Life is worth living again.
Oh wait. I just realised I have 3 more exams. Make that FOUR more exams.
Back to the gallows.

 

[m.incognito]

damn that was my initial answer for 6a then i was an idiot and went back and changed it, arggh

does anybody have the answer for 6b iv?

1480/3

 

[janiceee]

wouldn't 4)b)i be 179? as its 179.159 on my calc =S, nearest mm would be 179 not 180? or am i just wrong lol

nah i dont think you're wrong. i got ur exact ans too; 179.159..... and i put down 179
and i checked that a few times as well

 

[lightning9t]

4b i- 179
ii- n=13

4c
i (0,3)
ii (0,5)
iv 10.5 units^2

5b ii 19/40

6a x= pie/4, x=-pie/4 (im not to sure about this one)
b)i 20
ii 10
iii 6

I just done 4c) iv) i got 4/2/3 units^2, correct me if i'm wrong

 

[RohanZ]

i agree it was 215mm and 12 times, the first term had no zoom ins so it was with 60 that u started....it was a bit tricky..

For this question, in my answer, i wrote "At least 11 times" do you think that'll get me marks?

 

[betraya]

it had to be exact so n=12 or more

 

[emo-kid-91]

50 x 1.2 = 60 (first application)
60 x 1.2 = 72 (second application)
72 x 1.2 = 86.4 (third)
86.4 x 1.2 = 103.68 (fourth)
103.68 x 1.2 = 124.416 (fifth)
124.416 x 1.2 = 149.2992 (sixth)
149.2992 x 1.2 = 179.159 (seventh)
179.159 x 1.2 = 214.49 (eighth)

continuing on...

214.49 x 1.2 = 257 (ninth)
257 x 1.2 = 308.86 (tenth)
308 x 1.2 = 370 (eleventh)
370 x 1.2 = 444 (twelfth)

\o/ couldn't remember the formulas, so that's what i did.

 

[lightning9t]

what did people get for 4)c)iv)