We're going through the entire paper, posting answers. (1 Viewer)

Timothy.Siu

Prophet 9
Q10a. 5ln5 -4

b) i) a proof
ii)x=L/root2
iii) MP?=S(root2-1)

fryziesutton

New Member
series = 50, 60, 72...

a = 50 r = 1.2

the 8th zoom is the 9th term.

tn = ar^(n-1)

t9 = 50 x 1.2^8

= 214.99 mm = 215mm

ii)tn = ar^(n-1) = >400

50 x r^x = 400 ..... x = n-1

r^x = 8
1.2 ^ x = 8

log(1.2)8 = x

x = log 8
/log1.2

= 11.40

therefore it will be on the 12th zoom

fryziesutton

New Member
simpsons rule answer is 493 1/3

janaranaran!

Member
m.incognito said:
Question FIVE:

c) i) 6000
ii) 0.2986
iii) 298.6 lux/m
oops i think i got 5 c) iii) wrong... to get the rate of change I derived and got
dI/dk = -s x I

and when s = 6, I= 1000, so my rate of change was decreasing 6000 lux/m

what did i do wrong?

Question 6:

Timothy.Siu

Prophet 9
janaranaran! said:
oops i think i got 5 c) iii) wrong... to get the rate of change I derived and got
dI/dk = -s x I

and when s = 6, I= 1000, so my rate of change was decreasing 6000 lux/m

what did i do wrong?
I=/=1000
I=Ae^-kt
i dont know exactly wat u did wrong...

emo-kid-91

Cheer me up?
janaranaran! said:
oops i think i got 5 c) iii) wrong... to get the rate of change I derived and got
dI/dk = -s x I

and when s = 6, I= 1000, so my rate of change was decreasing 6000 lux/m

what did i do wrong?
you had to derive the whole formula after subbing in A and k.

Wingom

New Member
janaranaran! said:
oops i think i got 5 c) iii) wrong... to get the rate of change I derived and got
dI/dk = -s x I

and when s = 6, I= 1000, so my rate of change was decreasing 6000 lux/m

what did i do wrong?
well you're supposed to get.. dI/ds (because it asks for lux/m)
and dI/ds = -kI

= -1/6ln6*1000 = -298.6 (as many ppl have said..)
So.. then i guess you put it is decreasing at 298.6 lux/m

Last edited:

squeenie

And goodness knows...
m.incognito said:
Question 6:
Awesome. Looks like I got it right then.

m.incognito

lol.
Questions 7 - 10:

Rubes08

New Member
4c
i) (x-h)^2= 4a(y-k)
(x-0)^2= 4a(y-3)
therefore vertext (0,3)
ii) a=2 so focus (0,5)

sketch blah blah
iv) area argh. so find the x points so like when they intercept. can't remember them then integrate. i changed it so that y was the subject of equation.
I can't remember what i did for iv

Timothy.Siu

Prophet 9
m.incognito said:
Questions 7 - 10:
thanks i left early so they didn't let us take them

squeenie

And goodness knows...
Timothy.Siu said:
thanks i left early so they didn't let us take them
I stayed through the entire exam, and I still couldn't get my paper!

janaranaran!

Member
Wingom said:
well you're supposed to get.. dI/ds (because it asks for lux/m)
and dI/ds = -kI

= -1/6ln6*1000 = -298.6 (as many ppl have said..)
So.. then i guess you put it is decreasing at 298.6 lux/m
oooh i see, I did dI/dk instead of dI/ds, what with the k being the constant and such.
should still get 1/2 hopefully

YoungToby182

New Member
Guys.....WHO CARES! Its over - there isnt A SINGLE THING you can do right now.

Just forget about it and move on, and wait to see what ur results are.

Just wasting time, when you need to focus on the next approaching exam

Mongoz

DySFuNcTioNal
someone plZ show how u got 7a and 7c

JamesTockuss

Member
What did people get for 6(c) ?

JimmyJimJim

Member
emo-kid-91 said:
quoting from elsewhere...

Question 4 b)

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)
This isn't correct, or at least it doesn't comply with what I have written on my exam paper, did they round off too early or are those mis-labled. I have:

1. 50
2. 60
3. 72
4. 86.4
5. 103.68
6. 124.416
7. 149.2992
8. 179.15904
9. 214.990848
10. 257.9890176
11. 309.5868211
12. 371.5041853
13. 445.8050224

You cannot do a half-zoom, therefore, it had to be 13.