Paper 12 maths

[angelicsuccubus]

for that question..
part (i) yu had to use cosine rule=14.9
(ii) 45.9
(iii) 145.9

wasn't the plate the circular sector? (without the triangular part?)

 

[angelicsuccubus]

yeah same answers here

yep same.. what was k? I think I didnt do that right cause I got 7 1/9.. for the last function question.

 

[FarahT]

what was the last question like was it f(g)x? and what was g(x)? I solved this by b^2-4ac, is that right?

 

[FarahT]

does anyone remember what vectors OA and OB were?

 

[Aarjit]

wasn't the plate the circular sector? (without the triangular part?)

I'm afraid you're erroneous. The plate was circular with a vertical edge made by chord (AB) and not the 'dotted' circular sector which looked somewhat like Pacman.
The area is 146 cm^2 (correct to 3 s.f)

 

[Silent Hunter]

it was including the triangular part.

 

[Aarjit]

what was the last question like was it f(g)x? and what was g(x)? I solved this by b^2-4ac, is that right?

g-1(x)= (8/x) + 3 (x=/0)
you solve for the range of k by supposing the discriminant: b^2 -4.a.c<0
>> 0<k<(64/9)

 

[angelicsuccubus]

what about the G.P? did anyone get a=14?

I got 27 and i checked it.. cause ar= a - 9 and ar + ar^2= 30 so r=2/3 .. substitute back in and it works

 

[angelicsuccubus]

g-1(x)= (8/x) + 3 (x=/0)
you solve for the range of k by supposing the discriminant: b^2 -4.a.c<0
>> 0<k<(64/9)

YES! thankgod.. I got that too

 

[shanky631]

can anyone explain me how they got the answers for trigonometry question.

 

[angelicsuccubus]

My paper went very good, I'm hoping for something in the 70s if not full (I hate how elitist that sounds but meh :\) but yeah, I agree that the paper was quite tough and the grade threshold will definitely be low (probably 58-60 maybe).

I thought the paper was much easier than last year's .. except for 7a) everything made sense

 

[angelicsuccubus]

I'm afraid you're erroneous. The plate was circular with a vertical edge made by chord (AB) and not the 'dotted' circular sector which looked somewhat like Pacman.
The area is 146 cm^2 (correct to 3 s.f)

but but .. it said, "the plate was made by removing a triangular piece"... or somethin like that! ='[ .. I wrote 146 .. then re read the question and changed both answers I thin *sobsniffcry*

 

[angelicsuccubus]

it was including the triangular part.

look look >>https://docs.google.com/viewer?a=v&...c0M70X&sig=AHIEtbQmuARlg8o2JG4joxdGbACAi---Qw q7. Wasn't the wording of the question really similar to that? I remember calculating 146 and then going.. oh wait, but they removed the triangle!

 

[Silent Hunter]

In this one shaded areas were removed... but in the paper the question already had the part removed which wasnt shown ..... leaving behind the triangle and the remaning sector of circle

 

[sammykhan123]

When i solved the ap question i got d =1 and i put it in the equation and got a=9 ...how can u get a=9 if u get d=2 ?

 

[Ashmita]

what about the G.P? did anyone get a=14?

i got value of a in decimal ......... but i think my steps were correct ......... is there any chance of my answer being considered??

 

[123add1]

was the unit vector in direction of AB (-5i+6j)/square root of 61?

 

[leosco1995]

does anyone remember what vectors OA and OB were?

I don't exactly remember but I think OA was twice the magnitude of one of the vectors given in the question, and OB was thrice the magnitude of the other vector provided in the question. The final answer was something like 1/√61 (-5i + 6j).

 

[leosco1995]

was the unit vector in direction of AB (-5i+6j)/square root of 61?

Yes, it was this.

 

[confused123]

nope im damn sure its 12 pi

orryte congrats then :|