need to confirm some answers: (1 Viewer)

[gaoOO]

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]

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]

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!

 

[gaoOO]

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!

apart from the last question, 7 b)iv) i got all the same answers as you i think.

 

[gaoOO]

can someone explain why we take the positive case for the

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

 

[fishy89sg]

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]

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]

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~

 

[gaoOO]

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]

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.

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]

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

 

[fishy89sg]

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]

回复: Re: need to confirm some answers:

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

so are those answers confirmed

i got them too:wave:

 

[cc =)]

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]

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.

 

[gaoOO]

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

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

5) screwed up. :mad1:

 

[Hikari Clover]

回复: Re: need to confirm some answers:

Hmm.. well, gaa00 agrees with you, and someone in the general thoughts thread agreed with my answer 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]

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

 

[sting24]

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]

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