Mathematics: Post your doubts here!

[Kumkum]

thanx...wat bout the oda 3qs?

sorry forgot bout the others
here:
may/june 09
4ii)
From 4i) u got ur values for a,b and c.
a=6 b=2 and c=3, right?
so u jst put these values into this equation ur given and solve for x
====> y = 6sin(2x) + 3
so when y=0,
6sin(2x) +3 = 0
sin(2x) = -1/2
since you can't solve for negative values u can say:
let sin2x = 0.5
==> 2x = pi/6 (angles are in radians)
what i do frm here i let 2x = alpha (for alpha i'll use @)
so @ = pi/6
now you find the angles for sin where it is negative that will be in the 3rd and 4th quadrant
so,
in 3rd quadrant:
@ = pi + pi/6 = 7pi/6
in 4th quadrant:
@ = 2pi - pi/6 = 11pi/6 <-----this angle u can eliminate it coz u can see it's going to be the largest angle
now u can find x:
2x = 7pi/6
so, x = 7pi/12
hence the smallest is 7pi/12
i know its kinda long but thats how i do it, hope u understood

 

[Kumkum]

thanx...wat bout the oda 3qs?

oct/nov 09
9iii)
so frm 9ii) u had to find the gradients of AD and CD,
AD = 8/h and CD = -8/h-12
from the rectangle u shud see that gradient of AD and CD are perpendicular so u use the concept of 'm1m2 = -1', to equate the gradients nd find the x-coordinates.
so,
m1m2 = -1
(8/h)*(-8/h-12) = -1
-64/h^2 - 12h = 1
-64 = -h^2 + 12h
h^2 - 12h - 64 = 0
h^2 -16h + 4h - 64 = 0
h(h - 16) + 4(h -16) = 0
(h + 4)(h - 16) = 0
h = -4 or 16
so frm here u can straight away see that x-coordinate of B = -4 while for D = 16
hope u got it

 

[wajiman]

I have almost tried this several times but then I give up..Help me

sry i did not take maths

 

[Iffat]

sorry forgot bout the others
here:
may/june 09
4ii)
From 4i) u got ur values for a,b and c.
a=6 b=2 and c=3, right?
so u jst put these values into this equation ur given and solve for x
====> y = 6sin(2x) + 3
so when y=0,
6sin(2x) +3 = 0
sin(2x) = -1/2
since you can't solve for negative values u can say:
let sin2x = 0.5
==> 2x = pi/6 (angles are in radians)
what i do frm here i let 2x = alpha (for alpha i'll use @)
so @ = pi/6
now you find the angles for sin where it is negative that will be in the 3rd and 4th quadrant
so,
in 3rd quadrant:
@ = pi + pi/6 = 7pi/6
in 4th quadrant:
@ = 2pi - pi/6 = 11pi/6 <-----this angle u can eliminate it coz u can see it's going to be the largest angle
now u can find x:
2x = 7pi/6
so, x = 7pi/12
hence the smallest is 7pi/12
i know its kinda long but thats how i do it, hope u understood

wooow that is 1 looong ans..bt i understood ..thanx

 

[Iffat]

oct/nov 09
9iii)
so frm 9ii) u had to find the gradients of AD and CD,
AD = 8/h and CD = -8/h-12
from the rectangle u shud see that gradient of AD and CD are perpendicular so u use the concept of 'm1m2 = -1', to equate the gradients nd find the x-coordinates.
so,
m1m2 = -1
(8/h)*(-8/h-12) = -1
-64/h^2 - 12h = 1
-64 = -h^2 + 12h
h^2 - 12h - 64 = 0
h^2 -16h + 4h - 64 = 0
h(h - 16) + 4(h -16) = 0
(h + 4)(h - 16) = 0
h = -4 or 16
so frm here u can straight away see that x-coordinate of B = -4 while for D = 16
hope u got it

thanx..

 

[Iffat]

can sum 1 plz help wif d foll qs:
2009 oct-nov p12:
q10(i)(c)
2010 may-jun p11:
q1
q5(i)
2010 may-jun p12:
q1(i)
q11(iii)(iv)(v)

 

[Fatima18]

http://papers.xtremepapers.com/CIE/...AS Level/Mathematics (9709)/9709_w05_qp_6.pdf
Number 2 pls.

 

[Fatima18]

http://papers.xtremepapers.com/CIE/...AS Level/Mathematics (9709)/9709_s03_qp_6.pdf
Number 6 iii )
Please guys.???

 

[Rutzaba]

can sum 1 plz help wif d foll qs:
2009 oct-nov p12:
q10(i)(c)
2010 may-jun p11:
q1
q5(i)
2010 may-jun p12:
q1(i)
q11(iii)(iv)(v)

y dun u ppl buy solved solutions... they are very very help ful and they help u thru with p1 p3 s1 s2 m1 ...
there the explanations are way more lengthy

 

[A star]

can sum 1 plz help wif d foll qs:
2009 oct-nov p12:
q10(i)(c)
2010 may-jun p11:
q1
q5(i)
2010 may-jun p12:
q1(i)
q11(iii)(iv)(v)

can u provide link please

 

[Rutzaba]

ok ppl heres a website into wch if u post question it gives asnswers
http://www.wolframalpha.com/
go to examples

 

[Rutzaba]

and for tose who have stats ... https://www.xtremepapers.com/commun...xplained-by-mr-kurmally-binyamine-9709.24313/

 

[Alice123]

and for tose who have stats ... https://www.xtremepapers.com/commun...xplained-by-mr-kurmally-binyamine-9709.24313/

is dat a video?

 

[Rutzaba]

is dat a video?

yes

 

[snowbrood]

can anyone solve this question (9-x^2) given the limits from 0 to 3 solve this tell me why the answer is 18

 

[syed1995]

can anyone solve this question (9-x^2) given the limits from 0 to 3 solve this tell me why the answer is 18

I am assuming integrate?
(9-x^2) limits 3-0
Integral>9-x^2
9x-x^3/3
[9(3)-(3)^3/3] - [9(0) - 0^3/3]
=27 - 9
=18

 

[Fatima18]

http://papers.xtremepapers.com/CIE/...AS Level/Mathematics (9709)/9709_w07_qp_6.pdf
question 7 ii nd iii ???

 

[yousef]

I am assuming integrate?
(9-x^2) limits 3-0
Integral>9-x^2
9x-x^3/3
[9(3)-(3)^3/3] - [9(0) - 0^3/3]
=27 - 9
=18

for M1 ... eg when a lorry comes DOWN a hill ... how do we now if its gain/loss in kinetic energy ... when speed at top is given only ?????
ANY ONE

 

[Rutzaba]

http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_w12_qp_63.pdf

can anyone plz solve Q 2, Q5 (iii) and 6n(ii) n (iii) please

 

[airyhat]

http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_w09_qp_61.pdf
Q5 a(ii) b(ii) and Q6