Section I: Multiple Choice (2 Viewers)

[mreditor16]

top 5 at my school told me 9 was A - I guessed it cos of time, so idk.

 

[mreditor16]

Yeah I think aDimitris are correct except 9 should be A (I put B though lol)

exactly the same

 

[mreditor16]

I'm interested in Q9, I guessed B, but idk :/

 

[rumbleroar]

top 5 at my school told me 9 was A - I guessed it cos of time, so idk.

^

my friend is like top 5 as well and she confirmed 9 was A

 

[iStudent]

I got 10 as A
break it up then use u=-x to get A instantly

 

[mreditor16]

I got 10 as A
break it up then use u=-x to get A instantly

pree sure 10 is D

 

[iStudent]

10 as CCCCC sorry

 

[wagig]

Ohhhh, for 9, v is in terms of x, so you can't find acceleration by doing dv/dt

 

[iStudent]

Oh actually never mind. The answer I was looking for isn't there
Makes sense now ahha. Yea D looks right

 

[aDimitri]

if you break it up as f(-x) you get + f(-x) not - f(-x)! i nearly fell for that

 

[iStudent]

if you break it up as f(-x) you get + f(-x) not - f(-x)! i nearly fell for that

Yea I know but I was in a rush so I chose A :'(

 

[IR]

Here's what I got:
1. D
2. A
3. B
4. C
5. C
6. B (answer was D -.-)
7. A
8. B
9. B
10. D

Definitely got a few wrong, was worried about time

Isnt 7) B
fcking 8. So simple, misread the options and wrote A. Fcking 10, i got wring.

 

[IR]

pree sure 10 is D

Fcking hell. WTF, I though B said f(x)+ F(a-x).
But not sad to lose those two marks, because they were pree careless. But still a bit said- fcking why am I blind- Can someone tell me?

 

[mirachael]

DABCCDBBBD
Pretty sure they're all right except for 9 which should be A (silly me-gg first in state)
For D, I let F(x) be the primitive and worked from there

 

[danielblarg]

For 9, differentiating (A) I got dv/dx = 2cos(x-1), a = v.dv/dx = 2v.cos(x-1), sub x=1, v=2, a = 2(2).cos(0)=4

 

[dan964]

Yep, affirmed. Same answers except...
For Q10, let the primitive of f(x) be S(x). A only works for even (unfortunately I put that answer)...
D IS Q10 as above.

I will put questions up scanned by 5pm, with solutions maybe...

Multiple Choice
D, A, B, C, C, D, B, B, A, D

Tricks and Blunders:
(not mine)

Q11 b - make sure not to forget the 1/pi, or get the sign wrong.
Q11 e - integrate wrt y not x
Q12 a - label your axes, remember for (ii) if f(a)=0 then f(1/a) is undefined.
Q12d (ii) - evaluate the left hand side rather than trying to get a reduction formula.
Q13 b - find the height by splitting the trapezium into a parallelogram and equilateral triangle
Q13 c (iv) - let t=e, then find the slope of MS
Q14 a ii - don't do what I did which was long division, still get the same answer just takes longer
Q14 b i - angle between two lines, make sure to justify why a^2 - b^2 not b^2 - a^2
Q14 c i - at terminal velocity, a = 0
Q15 b ii - let n = 4x then work out and then simplify down
Q15 c i - find forces horizontally first to eliminate T and r, and then use the forces vertically to get the expression
Q15 c ii - use cos^phi = 1 - sin^phi then quadratic equation
Q15 c iv - use part (i)
Q16 a ii - use the tangents and the straight angles add up to 180, note: you will need to apply a similar method to part (i) again for circle 2
Q16 b i - didn't do, but guessing sum of a G.P.
Q16 b ii - use part (i) and integrate between 1 and 0
Q16 b iii - use part (ii) and let n go to infinity so middle term goes to 0
Q16 c - sub x = e^u, and notice it looks like a quotient rule in reverse...

 

[IR]

I got 10 as A
break it up then use u=-x to get A instantly

How'd u get A? It just can be A because if f(x) is even then A=0 and if f(x) is odd, then the original question is zero.

 

[aDimitri]

For 9, differentiating (A) I got dv/dx = 2cos(x-1), a = v.dv/dx = 2v.cos(x-1), sub x=1, v=2, a = 2(2).cos(0)=4

the only issue i'm having is that i did d/dx v^2/2 in order to check it, and it didn't work :S

 

[iStudent]

How'd u get A? It just can be A because if f(x) is even then A=0 and if f(x) is odd, then the original question is zero.

misread the minus sign

 

[iStudent]

It's D. :'(