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need to confirm some answers: (1 Viewer)

G

gaoOO

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vladimirv said:
What was the answer to the very last question, 7 b iv)
I got something very small like 0.16, and something larger.
I managed to finish the test with about 25 min remaining, and checked my whole paper except for 7 b)
So far nothing wrong i think
congrats, now post up your answers.

i can't believe i wrote down the ranges for the last question instead of the widths.
*bangs head against the table.
 

sting24

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gaoOO said:
i used the definite integral approach.

probably on the family one i got 1/5, did anyone else get that?
yea it was (4! x 3!)/6! which is 1/5
 

fishy89sg

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1. did people get 1.1664 for their answer in Question 5 (a) (ii)?

2. did u guys get pi^2 / 12 for question 3 (a)

3. did u guys get pi/4 for question 1 (d)

4. is the answer to question 7 (b) (iv) really 1.28metres and 0.159metres? and (iii) 0.8 <= m <= 1.2 ??

thanks in advance guys! :santa:
 
G

gaoOO

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fishy89sg said:
1. did people get 1.1664 for their answer in Question 5 (a) (ii)?

2. did u guys get pi^2 / 12 for question 3 (a)

3. did u guys get pi/4 for question 1 (d)

4. is the answer to question 7 (b) (iv) really 1.28metres and 0.159metres? and (iii) 0.8 <= m <= 1.2 ??

thanks in advance guys! :santa:
apart from the last question, 7 b)iv) i got all the same answers as you i think.
 
G

gaoOO

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can someone explain why we take the positive case for the

ln (x + root blah) etc. question (inverse)
 

fishy89sg

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gaoOO said:
can someone explain why we take the positive case for the

ln (x + root blah) etc. question (inverse)
im assuming its somethin to do with part (i)
 

sting24

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gaoOO said:
can someone explain why we take the positive case for the

ln (x + root blah) etc. question (inverse)
its + not negative because if its negative, then x + root(x^2 +4)/2 is negative, and this means that it would be f-1(x) = log (negative answer) which does not exist because logx can only be x>0, so its postive
 

missburwood

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isnt question d ii a trick question?
when you find x dont you need to minus it from 2000 ?I thought the x indicates where you would be awhen t=10???

maybe i was tricked arrghhhhhhh not sure
someone confirm this please~
 
G

gaoOO

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sting24 said:
its + not negative because if its negative, then x + root(x^2 +4)/2 is negative, and this means that it would be f-1(x) = log (negative answer) which does not exist because logx can only be x>0, so its postive
oh good, so it was ok for me to write

e^y > 0 therefore take positive case + etc.
 

Legham

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fishy said:
1. did people get 1.1664 for their answer in Question 5 (a) (ii)?

2. did u guys get pi^2 / 12 for question 3 (a)

3. did u guys get pi/4 for question 1 (d)

4. is the answer to question 7 (b) (iv) really 1.28metres and 0.159metres? and (iii) 0.8 <= m <= 1.2 ??

thanks in advance guys!
I didnt do the last one, but i had the same as you for the first 3.

miss burwood said:
isnt question d ii a trick question?
when you find x dont you need to minus it from 2000 ?I thought the x indicates where you would be awhen t=10???

maybe i was tricked arrghhhhhhh not sure
someone confirm this please~
"Find the distance that she has fallen in the first ten seconds."

How far she has travelled, not where she has travelled to. You were tricked.
 

blink376

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hey guys, how many solutions were there for 5(c) and what did people get for 6 (b)(iii), cheers.
 

fishy89sg

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OK,

1. so is the answer for question 2 (d) (ii) confirmed at 283m?

2. and are the answers for question 4 (a) (i) (ii) and (ii) confirmed at
0.01
0.285 and
0.43 respectively?

3. and how did you guys find the max value for h for question 7 (b) (ii)

4. for question 6 (a) (iv), were the 4 answers pi/4, 3pi/4, 5pi/12 and 7pi/12?

5. and final call for the confirmation of 7 (b) (iv) as
1.28metres and 0.159metres???? lol

thanks so much in assisting me calculate my estimate raw mark. :):):):):):):):):):):):):)
 

Hikari Clover

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回复: Re: need to confirm some answers:

fishy89sg said:
yeh i had 1.28metres and 0.159metres for the two distances....

so are those answers confirmed

i got them too:wave:
 

cc =)

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missburwood said:
isnt question d ii a trick question?
when you find x dont you need to minus it from 2000 ?I thought the x indicates where you would be awhen t=10???

maybe i was tricked arrghhhhhhh not sure
someone confirm this please~
yerrs that qn was tricky. It sounds right to minus 2000 from it and i forgot to do that =(

for qn 5 c, are there meant to be two values for each x and y ? or only one ?

grrs qn 7 >=/
 

Legham

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1. so is the answer for question 2 (d) (ii) confirmed at 283m?

2. and are the answers for question 4 (a) (i) (ii) and (ii) confirmed at
0.01
0.285 and
0.43 respectively?
Yeah. 99% sure.
 
G

gaoOO

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fishy89sg said:
OK,

1. so is the answer for question 2 (d) (ii) confirmed at 283m?

2. and are the answers for question 4 (a) (i) (ii) and (ii) confirmed at
0.01
0.285 and
0.43 respectively?

3. and how did you guys find the max value for h for question 7 (b) (ii)

4. for question 6 (a) (iv), were the 4 answers pi/4, 3pi/4, 5pi/12 and 7pi/12?

5. and final call for the confirmation of 7 (b) (iv) as
1.28metres and 0.159metres???? lol

thanks so much in assisting me calculate my estimate raw mark. :):):):):):):):):):):):):)
1) it was 283. xx but i can't remember which way it rounded. i hope i didn't round wrong.

2) i'm pretty sure about those ones

3) 3 - 0.4h > 0 therefore h < 7.5 :confused:

4) as mentioned, i got 11 pi/ 12 instead of 7pi /12

5) screwed up. :mad1:
 

Hikari Clover

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回复: Re: need to confirm some answers:

Legham said:
Hmm.. well, gaa00 agrees with you, and someone in the general thoughts thread agreed with my answer :p We'll soon find out lol.

edit: actually, im pretty sure you're right. me and the other girl forgot to add a constant when integrating i think.

wait,i found that the constant is 0,i use t=0 and x= 0 as the initial condition
 

mrzeidan1

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fishy89sg said:
OK,

1. so is the answer for question 2 (d) (ii) confirmed at 283m?

2. and are the answers for question 4 (a) (i) (ii) and (ii) confirmed at
0.01
0.285 and
0.43 respectively?

3. and how did you guys find the max value for h for question 7 (b) (ii)

4. for question 6 (a) (iv), were the 4 answers pi/4, 3pi/4, 5pi/12 and 7pi/12?

5. and final call for the confirmation of 7 (b) (iv) as
1.28metres and 0.159metres???? lol

thanks so much in assisting me calculate my estimate raw mark. :):):):):):):):):):):):):)
agreed on all questions.

maximum value of h, i set the stuff in the square root = 0 and solved for h?

edit: had an 11pi/12 somewhere in there though, cant remember exactly
 
Last edited:

sting24

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fishy89sg said:
4. for question 6 (a) (iv), were the 4 answers pi/4, 3pi/4, 5pi/12 and 7pi/12?
um i got all those exept 1pi/12, i think its 11pi/12
 

DJ99

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I worked out the distance the skydiver fell to be 283 just then, but 533 seems so familiar. Hope I didn't accidentally write 533.

Probability of green eyes-
i) 0.01
ii)0.285
iii)0.323
 

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