Mathematics: Post your doubts here!

[A*(a*)]

yup

People like you deserve heaven already in uni - still helping juniors.

 

[Rutzaba]

People like you deserve heaven already in uni - still helping juniors.

prayers wud be quite sufficient ^_^

 

[A*(a*)]

prayers wud be quite sufficient ^_^

May God bless you
remem me in the prayers too

 

[Rutzaba]

May God bless you
remem me in the prayers too

will do insha Allah

 

[A*(a*)]

will do insha Allah

 

[Rutzaba]

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wait thori der

 

[Rutzaba]

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wch year is this?

 

[A*(a*)]

wch year is this?

http://papers.xtremepapers.com/CIE/...S Level/Mathematics (9709)/9709_s10_qp_31.pdf
Q9.

 

[Rutzaba]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Mathematics (9709)/9709_s10_qp_31.pdf
Q9.

not by me
d/dx[(1 - x)/(1 + x)] = [(-(1 + x) - (1 - x))/(1 + x)²] using quotient rule for differentiation

= -2/(1 + x)²

Now y = √[(1 - x)/(1 + x)] = [(1 - x)/(1 + x)]^(½)

∴ dy/dx = (½)[(1 - x)/(1 + x)]^(-½)*(-2/(1 + x)²) using the chain rule for differentiation

dy/dx = -1/[(1 + x)^(3/2)√(1 - x)] or -1/[(1 + x)(√(1 - x²)] [using (1 + x)(1 - x) = (1 - x²) inside square root after splitting up (1 + x)^(3/2) into (1 + x)√(1 + x)]

dy/dx is the gradient of the tangent at the point (x, y) and since the normal is perpendicular to the tangent, its gradient will be the negative reciprocal of dy/dx (i.e. product of gradients = -1)

So gradient of normal will be (1 + x)√(1 - x²)

 

[Beyond650]

How do you form the differential equation from that long paragraph they usually give at the end of the P3 exam? Any advice or notes on that would be helpful.

Section 8 here. It's a fantastic resource. Do what "A star" wrote and there's a case when a variable is decreasing; you have to write a negative sign with the constant when that happens.
http://www.examsolutions.net/maths-revision/syllabuses/CIE/period-1/P3/module.php

 

[daredevil]

Question 10

 

[Sarah_3420]

Guys please tell me anything that can help with complex numbers its sooo tough especially the arg of z least or greatest and how to find the hypotenuse please jazak Allah khair.

 

[xX1234Xx]

Can someone break down permutations and combinations for me? I'm not sure in which situation to use what

 

[TERMINATOR]

Salaam. Can someone please explain the part 2 of thisquestion, I've been stuck here for a long time

 

[TERMINATOR]

Can someone break down permutations and combinations for me? I'm not sure in which situation to use what

This may help you.

http://www.mathsisfun.com/combinatorics/combinations-permutations.html

 

[A star]

Salaam. Can someone please explain the part 2 of thisquestion, I've been stuck here for a long time

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i think i posted a reply in the last few pages.

 

[Mstudies]

m2 Question on projectiles.

In a game of cricket, a batsman strikes the ball at a height of 1 meter. It passes over a fielder 7 meters from the bat at a height of 3 meters, and hits the ground 60 meters from the bat. How fast was the ball hit?

I tried solving this question using the equation of trajectory, but I have neither u nor θ
Because of the same reason i couldn't solve using other equations.
Any idea's
THX

 

[A star]

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Question 10

reference

 

[TERMINATOR]

i think i posted a reply in the last few pages.

Really? Ok let me check it out, thank u

 

[TERMINATOR]

the one that is quoted in his question
the equationi formed in the first part is
y=e^15(e^(-2t))+ln70)
now we know the inital mass is 70 so
p=(the long equation quoted above/70)*100
as t==> infinity p==> 1 there u go

How do we get 100/e ? (ans)