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

[m.incognito]

Shot gun question ONE:

a) 2cospi/5 = 1.62 to 3 s.f.

b) Factorise 3x^2 + x - 2 = (3x - 2) (x + 1)

c) Simplify 2/n - 1/(n+1) = (n+2)/(n^2 + n)

d) |4x - 3| = 7 x= 5/2 and -1

e) (rt3 - 1)(2rt3 + 5) = 1 + 3rt3

f) Sum of 1st 21 terms of 3+7+11... = 903

 

[emo-kid-91]

(i think i got these right. lol!)

question two:

a. i. 18x(x^2+3)^8

ii. 2xlnx + x

iii. xcox + 4cox - sinx / (x+4)^2

b. M = (2, 6)
x + 2y - 14 = 0

c. i. ln(x+5) + C
ii. 1/3

 

[syriangabsta]

full marks so far

 

[m.incognito]

Question FOUR:

a) < YRX = < XRQ (XR bisects <PRQ, given)
< XRQ = < RXY (alternate angels, XY||QR)
.:. Triangle XYR is isosceles (2 equal angles in triangle)

b) i) 215 mm
ii) 12 times

c) i) (0, 3)
ii) (0, 5)
iii) Yeah just show the points Looks like a normal parabola hoisted 3 up.
iv) 10 2/3 units

 

[-MikeY-]

c) Simplify 2/n - 1/(n+1) = (n+1)/(n^2 + n)



Sorry but you lost a mark here. its (n+2)/(n^2+n) - 2 x n+1 = 2n+2

 

[karnage]

b) i) 215 mm
ii) 12 times

13 times?

 

[m.incognito]

hahaha yeah mike you're right (pretty sure i got it right in the test this is me doing them post-test)

 

[emo-kid-91]

13 times?

this has already been argued. when working it out without any formulas, it comes out as 12. 50, the first value, is not a zooming in value and is therefore not part of the gp.

 

[farkmedead]

c) Simplify 2/n - 1/(n+1) = (n+1)/(n^2 + n)



Sorry but you lost a mark here. its (n+2)/(n^2+n) - 2 x n+1 = 2n+2

i don't get what you're saying but i remember my answer had i think (n+2)/(n^2+n)
i THINK.

also, does anyone have the test? i.e. the questions or remember them LOL

 

[Rampager]

c) Simplify 2/n - 1/(n+1) = (n+1)/(n^2 + n)

Say what?

2(n+1) - n
------------
n(n+1)


2n + 2 - n
------------
n(n+1)


= n + 2
---------
n(n+1)

full marks

I guess not anymore...


Question 4 b)
50 x 1.2 = 60 (first application)
60 x 1.2 = 72 (second application)
72 x 1.2 = 86.4 (third)
86.4 x 1.2 = 103.68 (fourth)
103.68 x 1.2 = 124.416 (fifth)
124.416 x 1.2 = 149.2992 (sixth)
149.2992 x 1.2 = 179.159 (seventh)
179.159 x 1.2 = 214.49 (eighth)

continuing on...

214.49 x 1.2 = 257 (ninth)
257 x 1.2 = 308.86 (tenth)
308 x 1.2 = 370 (eleventh)
370 x 1.2 = 444 (twelfth)


before anyone argues.

 

[syriangabsta]

Question 3:

(a)

(i) y2-y1/x2-x1 = 2. (for line BC)
y=2x -1, therefore m=2 (for line AD) therefore, parralell.

(ii) y-coordinate is 5, since its paralell to x-axis and its along with the point C.
x-coordinate.... 2x - y - 1 = 0. when y=5, 2x-5-1 = 0. x=3. Dis at (3,5)

(iii) distance formula. root(5) units

(iv) using perpindicular distance formula where...a=2, b=-1, c=-1, x=0, y=3
gets 4/root(5)

(v) A=h/2 (a+b)

Find distance of AD. which is 3root(5)
A = 1/2 . 4/root(5) . (root(5) + 3root(5))
= 1/2 . 4/root(5) . (4root(5))
= 16 units^2
(have i mistaken here?)


(b)

(i) d/dx = -sinx/cosx = -tanx

(ii) -1(lncos(pi/4))
= 0.3465....

 

[karnage]

370 x 1.2 = 444 (twelfth)


before anyone argues.

Ah.

I wrote something like n > 12.5ish or somethin
Then i just rounded it up to 13.

 

[syriangabsta]

Say what?

2(n+1) - n
------------
n(n+1)


2n + 2 - n
------------
n(n+1)


= n + 2
---------
n(n+1)



I guess not anymore...
.

lol nah, i got that question right. i just didnt look into the answer given in the 1st post, because in the exam i had checked it by substituting n for 2. so yeah. full marks is still there too bad i screwed up some later q's

 

[m.incognito]

Question FIVE:

a) Integral (1-6sin3x) = [x - (-6cos3x/3)] + c

y = x + 2cos3x + c​

When x = 0, y = 7​

7 = 0 + 2 + c​

c = 5​

.:. y = x + 2cox3x + 5​

b) i) x is between -.5 and .5
ii) 19/40

c) i) 6000
ii) 0.2986
iii) 298.6 lux/m

 

[farkmedead]

Say what?

2(n+1) - n
------------
n(n+1)


2n + 2 - n
------------
n(n+1)


= n + 2
---------
n(n+1)



I guess not anymore...


Question 4 b)
50 x 1.2 = 60 (first application)
60 x 1.2 = 72 (second application)
72 x 1.2 = 86.4 (third)
86.4 x 1.2 = 103.68 (fourth)
103.68 x 1.2 = 124.416 (fifth)
124.416 x 1.2 = 149.2992 (sixth)
149.2992 x 1.2 = 179.159 (seventh)
179.159 x 1.2 = 214.49 (eighth)

continuing on...

214.49 x 1.2 = 257 (ninth)
257 x 1.2 = 308.86 (tenth)
308 x 1.2 = 370 (eleventh)
370 x 1.2 = 444 (twelfth)


before anyone argues.

I FAIL THAT SHIT AHHHHH * SEE U ON THE NEWS AS THE SUICIDAL KID.

 

[Arithela]

whats the answer to 7c?

 

[emo-kid-91]

whats the answer to 7c?

well, we're not there yet. but i spose i can kick my chugging brain into gear.

i. complete the diagram.
ii. p (gg) + p (gxg) + p (xgg) = 1/9 + 2/27 + 2/27 = 7/27
iii. 1 - p (gg) - p (xx) = 1 - 1/9 - 4/9 = 4/9

yeah?

and i have to say, xena and gabrielle? lol! like gabrielle could beat xena.

 

[reynoldson]

the area

h/2(a+b)

= 4/2√5 (4√5)

=16√5/2√5

=8

 

[LiLBoBo]

the area

h/2(a+b)

= 4/2√5 (4√5)

=16√5/2√5

=8

AGREED! everyone has 16 or 32, and like wtf? just use your calculator(use brackets) and you'll get 8

 

[farkmedead]

AGREED! everyone has 16 or 32, and like wtf? just use your calculator(use brackets) and you'll get 8

agreed again i got 8