Pure Maths 12 today........

[balay]

Which question are you talking about ??

the one in which eq of tangent to curve was x/k+k and eq of curve was 4y=x^2 and value of k was askd....try to remember......it was q3 i think..

 

[bamteck]

The paper was somehow hard !
What do you think guys ?

 

[doorman1995]

was the radius 20 for last ques or 12 i dont remeber the question n well i did the vector one in a different way

 

[Iadmireblue]

Yeap the radius of the sector in the last question was twelve

 

[doorman1995]

n for unit vector i got 2/3 and -1

 

[doorman1995]

well for unit vector i firrst calculated vector AB the i calculated its magnitude interms of k n then equated it to 1

 

[kevin94]

the one in which eq of tangent to curve was x/k+k and eq of curve was 4y=x^2 and value of k was askd....try to remember......it was q3 i think..

I did it using another method but i got k=-1

i assumed that gradient of y=(1/k)x+c was 1/k
then i equated it with dy/dx of 4y=x^2
and by series of simultaneous equations i got k=-1

 

[kevin94]

radius

was the radius 20 for last ques or 12 i dont remeber the question n well i did the vector one in a different way

Radius was 20
But i'm not sure of the answers. I think that i made and error and got 34.6 for perimeter

 

[Anamol shrestha]

n for unit vector i got 2/3 and -1

my also same

 

[balay]

I did it using another method but i got k=-1

i assumed that gradient of y=(1/k)x+c was 1/k
then i equated it with dy/dx of 4y=x^2
and by series of simultaneous equations i got k=-1

yea k=-1 seems right....i was worried cause i didnt check my answers.......cuz i didnt have time to check em as my calculator stopped workin while solving q2...my luck:S

 

[iKhaled]

my also same

did we have to find the direction of vector AB or not ?

 

[Iadmireblue]

Yeap it was in the direction of AB
Anyone remember the angle question.the one about arithematic progression?
I think i got 19 or something for n

 

[kevin94]

What was the question 11 for perimeter?
was it the two lines from 1.2 and [(the arc joining the two tangents together) or (the two lines form the tangents to the origin)?]

 

[iKhaled]

if u use one wrong limits while calculating the volume obtained when the shaded region was rotated but everythin else is fine and u even added the pie..how many marks do u lose ?

 

[kevin94]

Yeap it was in the direction of AB
Anyone remember the angle question.the one about arithematic progression?
I think i got 19 or something for n

I got 18
a=3
d=2
sum= n/2 X (first + last)
360 = n/2 X (3+3+d(n-1))
720 = n(6+2(n-1))
720=6n+2n^2-2n
720= 4n + 2n^2
360=2n + n^2
(n-18)(n+20)=0
n=18

 

[Gunner7]

the q regarding b^2 - 4ac.......q3 i think......was k=-1?

Yup got K= -1

 

[Gunner7]

if u use one wrong limits while calculating the volume obtained when the shaded region was rotated but everythin else is fine and u even added the pie..how many marks do u lose ?

Probably 2, 1 for wrong limits and 1 for wrong answer.

 

[Gunner7]

how to do the equation of tangent. Do you hve to do dy/dx?

get Dy/Dx ,Substitute x=3 (I guess) to get the Gradient of tangent,substitute (3,1) to get C (not sure about the Coordinates tho,but that's the idea)

 

[hussamh10]

Yup got K= -1

yeah it was k=-1

 

[kevin24]

Does anyone know how to answer Q10(b) the minimum value of the curve and also to prove that its a minimum?