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

[auxx]

Exam answers are up on www.pasthsc.com.au

Q(7) [a] is wrong, its also e^3 and 1/e.
even a few more wrong, I know there not official.

 

[hairej1]

agreed again i got 8

yayy me too!
this is reassuring hahha

 

[Goody Proctor]

someone plZ show how u got 7a and 7c

7(a)

Solve: lnx - 3/lnx = 2

multiply by lnx..
(lnx)^2 - 3 = 2lnx
let lnx = a, making it a quadratic
a^2 - 2a -3 = 0
(a-3)(a+1)=0
therefore a = 3 , a = -1 ...but cant have a negative log, so just 3
3 = lnx
x=e^3 (put it into equation to check and it works)

7(c) was posted above already I think..

 

[erm]

e cubed is a solution however 1/e is also another solution as its lnx = -1 which does have a solution

+1

 

[teurino]

100000 x 1.005^n - M (1+1.005+1.005^2... + 1.005^n-1)

is that an alternative to answer given in pdf file with hsc 08 answers?

 

[sportylake]

think about it. if it comes to 12.5, then if its less than 12.5 you won't get at least 400, therefore it has to be 13 terms,

exactly. spot on.

 

[christiina.h]

what the hell

that series one is def 12

if you sub n=12 back into the sum formula then you get over 400
plus because the first term is actually n=0 because it hasn't been zoomed, hence why people got the final answer as being n>12.5 or whatever it was, but the answer is 12 times