solutions (2 Viewers)

[Nezz]

3a i: 18e^x(2e^x -4)^8

ii: 2xsinx + x^2cosx

3d i: Loge (x^2 + 5) + C

ii: (tan pi/3) - (tan pi/4)
= square root 3 - 1

 

[bails]

i got (pi tan)/12
thats so wrong isnt it

 

[Carla2003]

I wrote some of my answers on the sheet at the end, and I can't believe I actually wrote the derivative of sinx is sec<2 x----------if they know u have just accidently done something really stupid, do they give u the mark????

 

[Winston]

Originally posted by Carla2003
I wrote some of my answers on the sheet at the end, and I can't believe I actually wrote the derivative of sinx is sec<2 x----------if they know u have just accidently done something really stupid, do they give u the mark????

if they do that, then i would of got 90% in my trials
lol no they aren't that lenient, they would of thought you didn't know your stuff too well.

 

[vennyra]

Originally posted by Carla2003
if they know u have just accidently done something really stupid, do they give u the mark????

God i hope so, because for that question where we had to find the total distance travelled between 0 and pi, i did it between 0 and 2pi - you think i'll still get a mark for that?

 

[bails]

I couldnt even figure out the probability question coz i wasnt there at skool .... my fault mind u. i got 3/4 & 1/6. There wrong i no, but what u guys get?

 

[sneaker]

what answers did everyone get for the series question (q5B)? I'm not too confident that I was anywhere close...

 

[bails]

i got
i) 63
ii) 31
iii)5580

prob not right...but hey whats new!

 

[Beaky]

For Probability I got
i) 1/6 chance
ii) 1/12

For Series I got
i) 63
ii) 74
iii)3801

 

[Winston]

here's half of question 8 cant be bothered typing the rest im getting pissy with MS Eq Editor.

 

[natilucas]

These are just some I guessed, are they right?
Please hit me back if u think i've stuffed any up... I want to know my mark now!! Thanks anyway.
Q 2 (b) (vi) 25 units (squared)
Q 3 (a) (i) 18e^x(2e^x-4)^8
(ii) 2xsinx + x^2cosx
(b) Angle DPC = 180-(36+55) = 89 [alternate ang. par. lines.]
(c) Shades region was above x axis on left side
(d) (i) loge(x^2+5) + C
(ii) Root of 3 - 1
Q 4 (a) (i) 55 degrees
(ii) 64 degrees 28 minutes
(b) (i) 1 over 6
(ii) 1 over 2
(c) (i) A (1,-3)
(ii) 7 and a half units
Q 5 (a)(i) Just show
(ii) (3,-27) min, (0,0) horizontal turning pt.
(iii) Draw graph
(iv) 0<=x<=2 [(2,16) pt of inflection]
(b) (i) 63 blocks in 20th row
(ii) 74 rows
(iii) 3801 total blocks
Q 6 (a) (i) x=12
(b) (i) Angle EBD=Ang ABE which corres. (par. lines) to BCD
(ii) Angle BDC= Ang. EBD = BCD [alter. ang. on par. lines]
(iii) Similar Tri. side same ratio BD=BC isosceles
(c) (i) Co = 5, -k=0.579818495
(ii) 5.5 years
Q 7 (a) (i) -1<=r<=1, limiting sum = 11.something
(ii) r is not within -1 and 1
(b) (i) v=0 at rest Pi/3
(ii) Pi
(iii) Sketch, upside down usual cos about line +2
(iv) 6.3 something
Q 8 (a) y=-2
(b) btwn 5 and 1, log e y^2
(c) 6-2/6[f(2)+4f(4)+f(6)] = 5.9
(d) (i) substitute x= and y=
(ii) m= 1, 2/3
(iii) differentiate to find gradient substitute.
Q 9 (a) sinx= 1/2 or 2. x=pi/6, 5pi/6, 7pi/6, 11pi/6
(b) (i) BAO= pi/6 (30 degrees)
(ii) (3 X root3 X r^2) /4
(iii) (root3 X r^2) /4
(iv) (r^2 X pi)/6 - (2 X root3 X r^2)/4
(c) (i) substitute time = distance (L)/ speed (v-u)
(ii) 3u/2
Q 10 (a)(i) 120000(1+0.06/k) - F
(ii) don't know where the k came from?
(iii) $2324.47 ( nearest cent)
(iv) $498.35 (nearest cent)
(b) (i) sorta go it
(ii) Got common den. than x (top and bottom) by brackets down bottom. rationalises numerator.
(iii) hey it's only 2 marks i didn't get to put anything for???
anyone got a clue????
en elle

 

[Beaky]

This is the graph for question 7 iii) and axis go up by pi/3 on this graph...

 

[iambored]

Originally posted by sneaker
what answers did everyone get for the series question (q5B)? I'm not too confident that I was anywhere close...

i) 63
ii) 73
iii) i don't have it written, i did the sum of the first 20 rows, and then the sum of 13 more rows

 

[Sah]

(iii) hey it's only 2 marks i didn't get to put anything for???
anyone got a clue????

yeah i got that one i ended up with x=r for the answer and when i subbed it in it seemed to be correct.

In reply to the fish question i also got v = 3u/2 for the answer

For the bricks i think it may have been 73 rows (not 100% but fairly sure)

i think i stuffed up the last bit on the compound interest

 

[SmokedSalmon]

Looking at Q9 ii) I realised how CLOSE I was to getting it right. Somehow lol I got v = u - 2 (considering i had 5 sec left i think i derived it correctly anyway)... looking at the other solutions I'm feeling pretty happy maybe I might get over 100!
But since the paper was quite hard (as most people claim) um will it be scaled fairly?

 

[sneaky pete]

Originally posted by natilucas
Q 6 (c)
(ii) 5.5 years

ahh sorry, was just browsing through.i know for a fact i put down 5.6 years as the answer to this question
5.55(something...), i probably made an error substituting k back in, but just wondering what other people got, 5.5 or 5.6?


and for..

"(c) Shades region was above x axis on left side"

i shaded the region to the below (bottom right) and to the right side.. fuck im stuffed

 

[failingTheHsc]

Originally posted by sneaky pete
ahh sorry, was just browsing through.i know for a fact i put down 5.6 years as the answer to this question
5.55(something...), i probably made an error substituting k back in, but just wondering what other people got, 5.5 or 5.6?


and for..

"(c) Shades region was above x axis on left side"

i shaded the region to the below (bottom right) and to the right side.. fuck im stuffed

i got 5.6 and shaded that same region n im pretty sure we are right

 

[jackie_23]

I got 5.6 units too.
Good work

 

[tieki]

There are answers to q. 10 (a) done by a teacher on the Sydney Morning Herald website (www.smh.com.au)...i got at least 4/12 for q. 10...gotta be happy

 

[dnt stop runnin]

i shaded the region above the x-axis, on the right side after that line.....sound right??.......and yeh, i got 5.6 units