Author Topic: IGCSE MATHS Doubts  (Read 129881 times)

Offline Shazizzzle

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Re: IGCSE MATHS Doubts
« Reply #645 on: May 13, 2010, 10:17:20 am »
According to our teacher, order of rotational symmetry can never be 1.

It's either 0, 2 or 4.
And that image only turned back to it's position after one whole turn,
and...
EVERY IMAGE TURNS BACK TO ITSELF AFTER THE COMPLETE 360 deg,
So, the order or rotational symmetry was 0?

And the sinx-cosx=0.5, what do you suppose can be the range of the answers?

Also, what equation of line did you get in the intersecting lines one, the lat part?
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Offline dsiddiqi11

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Re: IGCSE MATHS Doubts
« Reply #646 on: May 13, 2010, 10:19:38 am »
According to our teacher, order of rotational symmetry can never be 1.

It's either 0, 2 or 4.
And that image only turned back to it's position after one whole turn,
and...
EVERY IMAGE TURNS BACK TO ITSELF AFTER THE COMPLETE 360 deg,
So, the order or rotational symmetry was 0?

And the sinx-cosx=0.5, what do you suppose can be the range of the answers?

Also, what equation of line did you get in the intersecting lines one, the lat part?

i got y=3x-13, but is this the question u are talking abt

Offline Shazizzzle

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Re: IGCSE MATHS Doubts
« Reply #647 on: May 13, 2010, 10:21:08 am »
i got y=3x-13, but is this the question u are talking abt


Umm, I'm referring to variant 2.

One thing, was the gradient of the line parallel to it 3, or -3?
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Offline haris94

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Re: IGCSE MATHS Doubts
« Reply #648 on: May 13, 2010, 10:21:28 am »
ANSWERS THAT I CAN REMEMBER:
rotational symmetry-1
lines of symmetry -1
rearranging thing x=3/(p-1)
white paint thing = 88
maximum speed of boris - 16.25
sin cos things- 45 degrees and 66 degrees
the very last graph qs - 82 i think and 108
the inequalites R- was in the slightly large area towards the middle/right

P.S. who agrees that the paper was definitely more difficult than past papers but still went super-awesome ;D ;D
I LOOOOVED IT


i got exactly the same answers  ;D

agreed, paper required more thinking but i think i (like Ari said) killed it  8)
WHAT WE DO IN LIFE ECHOES AN ETERNITY

Offline mohit1234

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Re: IGCSE MATHS Doubts
« Reply #649 on: May 13, 2010, 10:22:10 am »
i got y=3x-13, but is this the question u are talking abt

i got y=-3x+14

Offline haris94

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Re: IGCSE MATHS Doubts
« Reply #650 on: May 13, 2010, 10:24:01 am »
Umm, I'm referring to variant 2.

One thing, was the gradient of the line parallel to it 3, or -3?

the gradient was -3
cause the equation of parallel line was 3x+y=18
so it becomes y=18-3x

the equation finally is
y=-3x+14
WHAT WE DO IN LIFE ECHOES AN ETERNITY

Offline dsiddiqi11

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Re: IGCSE MATHS Doubts
« Reply #651 on: May 13, 2010, 10:26:37 am »
Umm, I'm referring to variant 2.

One thing, was the gradient of the line parallel to it 3, or -3?

i think its 3, cuz parallel lines have same gradient

Offline Shazizzzle

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Re: IGCSE MATHS Doubts
« Reply #652 on: May 13, 2010, 10:27:01 am »
the gradient was -3
cause the equation of parallel line was 3x+y=18
so it becomes y=18-3x

the equation finally is
y=-3x+14

Wow. :/
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Offline Dibss

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Re: IGCSE MATHS Doubts
« Reply #653 on: May 13, 2010, 10:29:32 am »
Umm, I'm referring to variant 2.
One thing, was the gradient of the line parallel to it 3, or -3?
i did variant2 and grad was -3

i got y=-3x+14
SAME :D

i got exactly the same answers  ;D
agreed, paper required more thinking but i think i (like Ari said) killed it  8)
WOOT WOOT ;D

Offline dsiddiqi11

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Re: IGCSE MATHS Doubts
« Reply #654 on: May 13, 2010, 10:31:10 am »
guys for the boris speed question, i didnt multiply my answer by 2 to get the max speed, so how many marks do i get, i showed all of the working

Offline haris94

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Re: IGCSE MATHS Doubts
« Reply #655 on: May 13, 2010, 10:34:33 am »
guys for the boris speed question, i didnt multiply my answer by 2 to get the max speed, so how many marks do i get, i showed all of the working

y do u hv to multiply the answer by 2  ???
i dont remember doing that
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Offline Dibss

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Re: IGCSE MATHS Doubts
« Reply #656 on: May 13, 2010, 10:36:23 am »
guys for the boris speed question, i didnt multiply my answer by 2 to get the max speed, so how many marks do i get, i showed all of the working
um what multiplying by2?
you find alonso's total dist. which was 130
then you do 1/2 x v x 16 = 130
v=16.25

Offline Choc.Kits

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Re: IGCSE MATHS Doubts
« Reply #657 on: May 13, 2010, 10:44:32 am »
the gradient was -3
cause the equation of parallel line was 3x+y=18
so it becomes y=18-3x

the equation finally is
y=-3x+14

Did that! Amazzzzzzing! :)
I came, I saw, I conquered biatches!

Offline Choc.Kits

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Re: IGCSE MATHS Doubts
« Reply #658 on: May 13, 2010, 10:46:11 am »
And its true, the first question, the rotational symmetry was 0. Cause you cant have a rotational symmetry of 1.

As far as i know, i lost out on the sinx - cosx = 0.5... i messed that sh*t up....
I came, I saw, I conquered biatches!

Offline Shazizzzle

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Re: IGCSE MATHS Doubts
« Reply #659 on: May 13, 2010, 10:47:41 am »
And I messed the gradient sh*t up.
So... 1 or 2 marks, either way, that's sh*t. :/
Crap.
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