Mathematics: Post your doubts here!

[leadingguy]

Hi.. Can someone pls help with nov11/33.q10 =S
here's the link
https://docs.google.com/viewer?a=v&q=cachel5TBi4TmzcJ:www.xtremepapers.com/papers/CIE/Cambridge%20International%20A%20and%20AS%20Level/Mathematics%20(9709)/9709_w11_qp_33.pdf november 2011 paper 33 9709&hl=en&gl=pk&pid=bl&srcid=ADGEESjynU7l4xl4mks2Y9oAnb1ghOQR75yUtAXuiAgJKP_3ljz5gDqaCPFYXCpxIS64HCC4oTVS4IwZIOBFrPlov_GWo38j47c-BwVoNuC1LpcY83kSTKful1Zt-ubLe1vbidh5Lf5D&sig=AHIEtbTfFEbI3bmoyd0Wnx3O3bppOVsZ_w

whats thiis lnk??

 

[Keitak]

Thanks for replying!
when you make X the subject does the answer you get have to be within the new range or the one specified in the question?

I get (2X-71.57)= 50.77 and 2x-71.57=(360-50.77)

2X=122.3 and 2X=380.8
X=61.2 X=190.4
in 2nd quadrant, only sin is +ve
then, do 360-190.4=169.6
then, 180-169.6=10.4

final answer should be in range specified in the question

why is it "360-50.7"
I dont undestand this part
"in 2nd quadrant, only sin is +ve
then, do 360-190.4=169.6
then, 180-169.6=10.4"

 

[iqraa nadeem]

MYy bad ..here's the link for nov11/33 i need help with q10
http://www.xtremepapers.com/papers/...S Level/Mathematics (9709)/9709_w11_qp_33.pdf

 

[iqraa nadeem]

I also need help with nov10/33 q10 part b (ii)
http://www.xtremepapers.com/papers/...S Level/Mathematics (9709)/9709_w10_qp_33.pdf

 

[Aahliya]

i had the same problem
what i did first was to make lny the subject ---> lny=(2x+1)/x
now differentiate each side ------> lny becomes 1/y (dy/dx)
differentiate (2x+1)/x using quotient rule ------- [2x-(2x+1)]/x^2 = -1/x^2
therefore------- 1/y (dy/dx)= -1/x^2,
take 1/y to the other side becomes ------− - y/x^2

Well !! That's the only way left to solve this question .. Nyz thanks

 

[iqraa nadeem]

Also with http://www.xtremepapers.com/papers/...S Level/Mathematics (9709)/9709_s11_qp_31.pdf
q8 part ii and iii

 

[iqraa nadeem]

I'll be so much thankful, if someone helps me with these =/
here's the link for nov11/33 i need help with q10
http://www.xtremepapers.com/papers/...S Level/Mathematics (9709)/9709_w11_qp_33.pdf

Also with http://www.xtremepapers.com/papers/...S Level/Mathematics (9709)/9709_s11_qp_31.pdf
q8 part ii and iii

 

[redapple20]

Hey can sum 1 tl me tat Formula wen we integrate and we Cant use ln because the power of x in the denominator
is Not linear? The 1 tat goes like 1/a and tan sumthing?
plx tel asap have ppr tommz!

 

[Chooi1993]

How to get the initial value for q4 ?​

http://www.xtremepapers.com/CIE/International A And AS Level/9709 - Mathematics/9709_s11_qp_32.pdf​

I cant understand . Can u give me the solution ?

 

[kinal]

why is it "360-50.7"
I dont undestand this part
"in 2nd quadrant, only sin is +ve
then, do 360-190.4=169.6
then, 180-169.6=10.4"

cos is only +ve in the 4th quadrant, meaning it is -ve in quadrant 2 and 3
cos 169.6 gives u -0.9835....u have to get a +ve value for X... u could just do 180-169.6.
cos 10.4 is +ve...m not sure if this is clear.

 

[Chooi1993]

How to get the initial value for q4 ?​

http://www.xtremepapers.com/CIE/International A And AS Level/9709 - Mathematics/9709_s11_qp_32.pdf​

 

[Mobeen]

http://www.xtremepapers.com/papers/...AS Level/Mathematics (9709)/9709_s03_qp_3.pdf
http://www.xtremepapers.com/papers/...hematics (9709)/9709_s03_ms_1+2+3+4+5+6+7.pdf
Q2(ii) . the integral of cotx is ln sinx . but after substituting the limits how can we get the answer stated ?

 

[angelicsuccubus]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s03_qp_3.pdf
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s03_ms_1 2 3 4 5 6 7.pdf
Q2(ii) . the integral of cotx is ln sinx . but after substituting the limits how can we get the answer stated ?

Oh I did that question in the morning..

 

[Mobeen]

Oh I did that question in the morning..
View attachment 9658

oh ! thanks a lot !

 

[angelicsuccubus]

guys which integrations and differenciations for trig do we have to know?

 

[Keitak]

cos is only +ve in the 4th quadrant, meaning it is -ve in quadrant 2 and 3
cos 169.6 gives u -0.9835....u have to get a +ve value for X... u could just do 180-169.6.
cos 10.4 is +ve...m not sure if this is clear.

thanks for your help I finally undestand it!

 

[angelicsuccubus]

oh ! thanks a lot !

anytime =]

 

[angelicsuccubus]

Hey can sum 1 tl me tat Formula wen we integrate and we Cant use ln because the power of x in the denominator
is Not linear? The 1 tat goes like 1/a and tan sumthing?
plx tel asap have ppr tommz!

you mean the uv method? ...

 

[redapple20]

No 1/tan inverse sumthing

 

[Khoo Hing Yee]

How to know the Argand diagram should be a circle or parallelogram ?