Solutions (2 Viewers)

[darkwarrior2]

even if you cross an answer out dont the markers mark it?

dont think so >< teacher said they dont look at crossed out answers.

 

[renya]

really? i got told that even if u scribbled everything out the markers were required to read it, in case you get some marks

 

[Libbster]

really? i got told that even if u scribbled everything out the markers were required to read it, in case you get some marks

that's true, one of the teachers at our school is a hsc marker and he said just put a line thru stuff cos u may be able to get a mark or two

 

[darkwarrior2]

lol i hope so

 

[TimmyDD]

Yep! markers are required to look at all ur scribbled out work...if you've shown knowledge in attaining the right answer, then crossing it out, you still recieve the appropriate marks

 

[annie_sinc]

these solutions are so depressing, looks like ill only be getting 42/84 max

 

[tim_dawborn]

Complete Solutions

YAY DONE
i was now bothered to complete them - here they are - may be few mistakes :S

if some super admin person wasnts to move them somewhere else so more people can find them easily, please do so

MOVED TO HERE :: http://community.boredofstudies.org/showthread.php?t=90373

phoenix

ps . sorry about being a zip but they were just over the upload limit grr

 

[haboozin]

for Qbii, for it to have only one solution

the minimum has to be bigger thna a root (ie put minimum in there and u have to get bigger than 0

that works out

and it has to be true

since if min is bigger than 0

then it'll only have 1 root and that is when the max is coming down again..

i did that and got the answer - so it must be right...

gap filled.

 

[tim_dawborn]

chears mate

 

[haboozin]

and Q6b ii ...

is it 44.82??

eek i think i wrote 40.82


3d ii

differentiate
x = l/2
check its a min (differentiate again or something)

put it in the equation

L^2/4 - L^2/2 +12 = 0
12 = L^2/4
L^2 = 48
L = 4 srt 3?
??

 

[robbo_145]

and Q6b ii ...

is it 44.82??

eek i think i wrote 40.82

i also wrote 40.82 since it would be double the time to maximum height........

 

[thunderdax]

40.82 is right. Phoenix just made a typo there i think.

 

[tim_dawborn]

40.82 is right. Phoenix just made a typo there i think.

yep my bad ... again

 

[menty]

Thats right.

FFS, im stupid, i wokred out x= rt12, and forgot to sub it back in the eqn to get l = 2rt12

 

[thunderdax]

Sry for picking out mistakes mate, but there's another one in question 7a (i)
dr/d(alpha)=0.5*2050sec.......
You made a minor mistake in differentiation.

 

[tim_dawborn]

yep thanks - quite hard doin it typed
stupid little things like that happen

slightly updated the solutions - fixed up some mistakes

 

[stv_87]

does any one have a definate solution for the minimum chord question, last p[art of three,

 

[menty]

well, i asked about this...(cuz i got x=rt12), needed to sub back in to get l

3d ii) x = sqrt 12, but the question asks for L, so L = 2 sqrt 12


Terry Lee
Phone: (02) 8725 4930, Mobile: 0410 536 065, Fax: (02) 9012 0881
Email: terrylee1@optusnet.com.au
Website: www.hsccoaching.com

 

[tim_dawborn]

SOLUTIONS http://community.boredofstudies.org/showthread.php?t=90373

 

[AreYouAlright?]

3d ii) x = sqrt 12, but the question asks for L, so L = 2 sqrt 12


Terry Lee
Phone: (02) 8725 4930, Mobile: 0410 536 065, Fax: (02) 9012 0881
Email: terrylee1@optusnet.com.au
Website: www.hsccoaching.com

I love Terry Lee so F$#%ing much right now, i did this by setting the discriminant equal to zero i didn't know what elso to do.. gave me 4 sqrt 3 which is this answer. Yes, i rule! Of course so does Terry Lee!