Mathematics: Post your doubts here!

ZaqZainab

ZaqZainab

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Thought blocker said:
HOW TO DO THIRD PART ?
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kitkat <3 :p said:
Can It be cos(k) ...thats the only thing tht comes in my mind :"/
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sorry for the late reply went for lunch
sinx=??
we know tanx=sinx/cosx
so sinx=tanx*cosx
square all the terms
sin^2 s= tan^2 x * cos^2 x
tanx=k
so tan^2 x= k^2
and cos^2(x)=1-sin^2 x
sin^2 x = k^2 *(1-sin^2x)
sin^2 x= k^2-(k^2*sin^2 x)
sin^2x + (k^2*sin^2 x)= k^2
sin^2 x (1+k^2)=k^2
sinx= root of(k^2 /(1+k^2))
sinx= k/root of(1+k^2)
 
ZaqZainab

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M Haseeb Javed said:
View attachment 40518

Part iii and iv ??
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iii) its hard to find the number of different arrangements which do not have all 4 vowels (E, E, A, E) next to each other directly so we will find all the possible arrangement which DO have 4 vowels next to each other first (E,E,A,E) can be placed in 8 different places
So (8!*4!)/(2!*2!*3!)=40320
and now find the total number of different arrangements
it will be (11!/3!*2!*2!)=1663200
1663200-40320= 1622880
iv)no Rs and no Ms
leave us with 7 letters
and at least 2 means either 2 or 3
now we have already take 2 E(s) we need 2 more letter (other than E) to get total of 4
4C2
now if we take all 3 E(s) we need 1 more to get total of 4
4C1
4C2+4C1=10
 

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kitkat <3 :P

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ZaqZainab said:
sorry for the late reply went for lunch
sinx=??
we know tanx=sinx/cosx
so sinx=tanx*cosx
square all the terms
sin^2 s= tan^2 x * cos^2 x
tanx=k
so tan^2 x= k^2
and cos^2(x)=1-sin^2 x
sin^2 x = k^2 *(1-sin^2x)
sin^2 x= k^2-(k^2*sin^2 x)
sin^2x + (k^2*sin^2 x)= k^2
sin^2 x (1+k^2)=k^2
sinx= root of(k^2 /(1+k^2))
sinx= k/root of(1+k^2)
Click to expand...
Thank u :)
 
Thought blocker

Thought blocker

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Wolfgangs said:
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w13_qp_12.pdf

I noticed that in many papers, many questions like Q1 come. How to solve such questions. Please reply as soon as possible
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ZaqZainab said:
There are this formulas
this might help
2014-04-13-21-20-06-jpg.40515
Click to expand...
:)
 
Rutzaba

Rutzaba

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Wolfgangs said:
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_w13_qp_12.pdf

I noticed that in many papers, many questions like Q1 come. How to solve such questions. Please reply as soon as possible
Click to expand...
bhai dekho
if cos x= p
cos^2 x= p^2
1- cos^2 x= 1- p^2
sin^2 x= 1-p^2 <---- cos square plus sin square =1
sin x= root of 1- p^2

second part
tan= sin/cos
see sin in terms of p divided by cos in terms of p
tan x=(root of 1- p^2)/p
 
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