Mathematics: Post your doubts here!

[madan159]

Re: Math As and A2 help

hi would anyone solve Q.no. 4 question of iteration.

 

[eyamwir]

Assalammualaikum,

i need help. this isnt really a qs from pyp but i sort of get this qs out of nowhere. it just popped into my head. do you have any idea how to solve this qs?

 

[Abdulrab]

no ur vol answe is wrong !!! you had to take 8 and 0 as the limits to find out the volume of the curve !!

 

[AlphaCentauri]

no ur vol answe is wrong !!! you had to take 8 and 0 as the limits to find out the volume of the curve !!

Thanks for answering. But yeah, that's exactly what I did.

Someone told me that because the curve was a circle, we had to divide the answer by 2. I don't get this at all.

 

[Parfals]

A Funnel Has A Circular Top Of Diameter 20cm And A Height Of 30cm. When The Depth Of Liquid In The Funnel Is 12cm, The Liquid Is Dripping From The Funnel At A Rate Of 0.2cm^3/s. At What Rate Is The Depth Of The Liquid In The Funnel Decreasing?

I need help immediately n please explain step by step
thnx in advance........

 

[Parfals]

Maths immediate help required plzzz help me out

A Funnel Has A Circular Top Of Diameter 20cm And A Height Of 30cm. When The Depth Of Liquid In The Funnel Is 12cm, The Liquid Is Dripping From The Funnel At A Rate Of 0.2cm^3/s. At What Rate Is The Depth Of The Liquid In The Funnel Decreasing?
from- pure maths 1 by Hugh Neil and Douglas Quadling
page numbr 183, Question 9
I need help immediately n please explain step by step
thnx in advance........

 

[leosco1995]

A Funnel Has A Circular Top Of Diameter 20cm And A Height Of 30cm. When The Depth Of Liquid In The Funnel Is 12cm, The Liquid Is Dripping From The Funnel At A Rate Of 0.2cm^3/s. At What Rate Is The Depth Of The Liquid In The Funnel Decreasing?

I need help immediately n please explain step by step
thnx in advance........

Read this post, answered by hassam.

 

[Parfals]

thnx a lot dude :good: :Bravo: :Yahoo!:

 

[rz123]

http://www.xtremepapers.com/CIE/Interna ... _qp_11.pdf
Q.2 how is it done ? Q.4 also thanks !

 

[unique840]

http://www.xtremepapers.com/CIE/International%20A%20And%20AS%20Level/9709%20-%20Mathematics/9709_w10_qp_11.pdf
Q.2 how is it done ? Q.4 also thanks !

2) expand the expression upto x^3
expansion will be:
1 + 6ax + 15(a^2)(x^2) + 20(a^3)(x^3)
it is given that coefficient of x is -30
so 6ax = -30x
6a = -30
a = -5
now put the value of a in the term x^3
it will be 20[(-5)^3]
it will be -2500

 

[unique840]

http://www.xtremepapers.com/CIE/International%20A%20And%20AS%20Level/9709%20-%20Mathematics/9709_w10_qp_11.pdf
Q.2 how is it done ? Q.4 also thanks !

4 i) [sinx(sinx/cosx)] / (1 + cosx)
[(sin^2)x ] / [cosx(1-cosx)]
(1-cos^2x) / [cosx(1-cosx)]
1-cos^2x can be written as (1-cosx)(1+cosx) according to the formula of a^2 - b^2 = (a+b)(a-b)
[(1-cosx)(1+cosx)] / [cosx(1-cosx)]
(1+cosx) / cosx
(1/cosx) + (cosx/cosx)
(1/cosx) + 1
1 + (1/cosx)
hence proved

ii) [(cosx + 1) / cosx] + 2 = 0
(cosx + 1 + 2cosx) / cosx = 0
3cosx + 1 = 0
cosx = -1/3
basic angle = cos inverse of (1/3)
basic angle = 70.5 degrees
x = 180 - 70.5
= 109.5 degrees
x = 180 + 70.5
= 250.5 degrees

 

[ching293]

Re: Math As and A2 help

hi would anyone solve Q.no. 4 question of iteration.

 

[markskoop]

plz....really need help wid this question...6(iii).follow dis link................http://www.xtremepapers.com/CIE/Interna ... _qp_63.pdf

 

[XPFMember]

Assalamoalaikum!!

I need help with Q:2 (ii) of June:2011 Paper:62.

JazakAllah Khair!

 

[markskoop]

this is because np>5 amd nq>5........as 30*.8=24 and 30*.2=6.hence normal approximation is jsutfied.......

 

[anahita16]

plz....really need help wid this question...6(iii).follow dis link................http://www.xtremepapers.com/CIE/Interna ... _qp_63.pdf

I'll go by the m.s.
Mrs Brown 3- She has to be in the front row. There are 3 seats in the front row, so there are 3 possibilities for Mrs Brown.
Mrs Lin 10- She jas to sit behind a student. In total there are 10 ways she can do this, bearing in mind that one of the front row seat will be occupied by Mrs Brown.
Student 5 - There are 5 students, Mrs Lin could be behind any one of these five. That makes 5 possibilties.
no of possible arrangements=3 × 10 × 5 × 11P9
but total no of arrangement= 14P12
Probability = 3 × 10 × 5 × 11P9 / 14P12
= 0.0687

 

[markskoop]

m sorry bt i didn't get it completely...................

 

[anahita16]

Which part(s) u didn't understand?
The seating arrangement possibilities or the final calculations?

 

[XPFMember]

assalamoalaikum!!

this is because np>5 amd nq>5........as 30*.8=24 and 30*.2=6.hence normal approximation is jsutfied.......

np is mean..thats fine but whats nq and is there any reason why is it so?

 

[markskoop]

nq is n(1-p)...i.e...q is 1-probability(p)......ya and normal distribution is always used if both np>5 and nq>5..if either of d values is less dan 5 den,,,binomial distribution is preferable rather than normal.......