Author Topic: IGCSE MATHS DOUBTS HERE !!!!  (Read 39695 times)

Offline astarmathsandphysics

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Re: IGCSE MATHS DOUBTS HERE !!!!
« Reply #150 on: October 30, 2011, 05:10:05 pm »
Try this too
An enlargement is always a multiple of the identity matrix

Offline imrohan

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Re: IGCSE MATHS DOUBTS HERE !!!!
« Reply #151 on: October 30, 2011, 05:11:03 pm »
Thank you but anything else that's really important? Any questions which are surely coming?

Offline astarmathsandphysics

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Re: IGCSE MATHS DOUBTS HERE !!!!
« Reply #152 on: October 30, 2011, 05:12:21 pm »
The first question will certainly be there.

Offline astarmathsandphysics

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Re: IGCSE MATHS DOUBTS HERE !!!!
« Reply #153 on: October 30, 2011, 05:13:04 pm »
And the las, and all the ones in between

Offline NotAbod

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Re: IGCSE MATHS DOUBTS HERE !!!!
« Reply #154 on: October 30, 2011, 05:14:06 pm »
Good one, lol.

Offline Star xD

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Re: IGCSE MATHS DOUBTS HERE !!!!
« Reply #155 on: October 30, 2011, 05:16:18 pm »
Try this too
An enlargement is always a multiple of the identity matrix

Thanks. :)

So, is it okay to multiply the co-ordinates of the object with the scale factor for co-ordinates of the image?

Offline astarmathsandphysics

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Re: IGCSE MATHS DOUBTS HERE !!!!
« Reply #156 on: October 30, 2011, 05:19:25 pm »
yes if the centre of enlargement is the origin. That is what I assumened when I said the matrix for an enlargement is a multiple of the identity.
Notice too that if the scale factor is k, the area is multiplied by k^2

Offline Star xD

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Re: IGCSE MATHS DOUBTS HERE !!!!
« Reply #157 on: October 30, 2011, 05:21:37 pm »
yes if the centre of enlargement is the origin. That is what I assumened when I said the matrix for an enlargement is a multiple of the identity.
Notice too that if the scale factor is k, the area is multiplied by k^2

Thanks a lot. :)
« Last Edit: October 30, 2011, 05:24:56 pm by Star :D »

Offline daniyal

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Re: IGCSE MATHS DOUBTS HERE !!!!
« Reply #158 on: November 17, 2011, 04:00:14 pm »
pls tell this, A,B,C,D 4 corners of rectangular plot on level grnd. bearing of b from a is 40, and bearing of c from a is 90.

calculate bearig b frm c, a frm c, d frm c!

Offline daniyal

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Re: IGCSE MATHS DOUBTS HERE !!!!
« Reply #159 on: November 17, 2011, 04:02:28 pm »
pls answer soon!

Offline astarmathsandphysics

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Re: IGCSE MATHS DOUBTS HERE !!!!
« Reply #160 on: November 17, 2011, 07:49:01 pm »
For answer to bearing question see attachment

Offline ~ Miss Relina ~

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Re: IGCSE MATHS DOUBTS HERE !!!!
« Reply #161 on: April 21, 2012, 12:01:50 am »
guys it is really urgent please help here guys it is really urgent please help here
 http://www.xtremepapers.com/papers/CIE/Cambridge%20IGCSE/Mathematics%20(0580)/0580_w05_qp_4.pdf

Q 7 ( c)(ii)
~~~Yarab everything turns alright at the end ~~~
    -----------Ameeeeeeeeeeen------------

Offline Dhampiresa

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Re: IGCSE MATHS DOUBTS HERE !!!!
« Reply #162 on: May 12, 2012, 10:35:13 am »
how to solve this, which co-ordinates i need to use to find the inverse :S!

http://www.xtremepapers.com/papers/CIE/Cambridge%20IGCSE/Mathematics%20(0580)/0580_s11_qp_42.pdf

question 8 (b) (ii)

Offline Saladin

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Re: IGCSE MATHS DOUBTS HERE !!!!
« Reply #163 on: October 02, 2012, 06:38:21 pm »
how to solve this, which co-ordinates i need to use to find the inverse :S!

http://www.xtremepapers.com/papers/CIE/Cambridge%20IGCSE/Mathematics%20(0580)/0580_s11_qp_42.pdf

question 8 (b) (ii)

Not inverse, this is simply stretch. Check your IGCSE Math book in the Matrices chapter, you should have an example like this there. I am not going to solve it for you, because then you would not learn what its all about.

Offline astarmathsandphysics

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Re: IGCSE MATHS DOUBTS HERE !!!!
« Reply #164 on: October 03, 2012, 10:10:15 am »
The pool empties at a rate of V=pi r^2 h =pi *12.5^2 *14 =6872 cm^3/s
Divide the amount of water in cm^3 by this. I make the volume 1.512*10^9
the time is 1.512*10^9/6872=220000 seconds
or 220000/3600 =61 hours or 2 days 13 hours