Author Topic: Math P1 Questions/Predictions  (Read 2135 times)

Offline Recko

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Math P1 Questions/Predictions
« on: May 11, 2010, 08:16:53 am »
Hey Guys


I'm Going to start with myself first, please oct/nov 05, question 9 part iii

i've found out that tan x= gradient, where x is the angle between the line and the x-axis is that correct?

if so, then why do you find the difference between the two angles anyways?

thanks in advance
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Offline nipuna92

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Re: Math P1 Questions/Predictions
« Reply #1 on: May 11, 2010, 08:45:57 am »
Because you have to find the angle between the 2 lines

nid404

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Re: Math P1 Questions/Predictions
« Reply #2 on: May 11, 2010, 08:46:32 am »
hold i'll get you the post...I've answered this before

nid404

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Offline Recko

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Re: Math P1 Questions/Predictions
« Reply #4 on: May 11, 2010, 09:07:15 am »
THANK YOU SO MUCH! =D
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nid404

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Re: Math P1 Questions/Predictions
« Reply #5 on: May 11, 2010, 09:18:52 am »
no problem  :)

Offline Recko

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Re: Math P1 Questions/Predictions
« Reply #6 on: May 11, 2010, 09:41:55 am »
I have another question

oct/nov 06
question 9 i) & ii)

:)
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Offline Padapop

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Re: Math P1 Questions/Predictions
« Reply #7 on: May 11, 2010, 09:46:30 am »
or you could try vector method.

I use it and i find it easier, though some ppl might find it weird.

The tip is to use your gradient as a vector. Then u dot product them.

Offline nipuna92

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Re: Math P1 Questions/Predictions
« Reply #8 on: May 11, 2010, 10:27:46 am »
can u show the dot product thing here

Offline Padapop

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Re: Math P1 Questions/Predictions
« Reply #9 on: May 11, 2010, 10:40:33 am »
oh..

so for example, if the first line's gradient is = 2. that would be 1i + 2j. And the second line's gradient is 3/2, that would be 2i + 3j.

(1i + 2j) . (2i + 3j) blah blah blah the dot product formula.

U could try it, but i think nid's one is standard mark scheme thing, so that way is more standard. Ull get the same answer thou.

Offline nipuna92

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Re: Math P1 Questions/Predictions
« Reply #10 on: May 11, 2010, 10:43:02 am »
oh..

so for example, if the first line's gradient is = 2. that would be 1i + 2j. And the second line's gradient is 3/2, that would be 2i + 3j.

(1i + 2j) . (2i + 3j) blah blah blah the dot product formula.

U could try it, but i think nid's one is standard mark scheme thing, so that way is more standard. Ull get the same answer thou.

thanx got it ;) ;)

Offline Recko

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Re: Math P1 Questions/Predictions
« Reply #11 on: May 11, 2010, 11:29:01 am »
Guys, i finished all papers,and i cracked every single question! and i know everything!

what do you think i should do now?
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Offline astarmathsandphysics

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Re: Math P1 Questions/Predictions
« Reply #12 on: May 11, 2010, 11:32:12 am »
Start P2
Jump for joy
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Offline Recko

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Re: Math P1 Questions/Predictions
« Reply #13 on: May 11, 2010, 11:38:59 am »
hahaha start P2? i still didnt do the exam sir :P and no thanks ill pass :P

hahaha my president?

sir can you please help me out in oct/nov 06 question 9 i) and ii)
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nid404

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Re: Math P1 Questions/Predictions
« Reply #14 on: May 11, 2010, 11:56:30 am »
What am i here for ? ;)

9)total surface area=200

10xy(the 2 sides) + 24x2(the 2 triangles)=200

10xy=200-24x2
     y=200-24x2/ 10x

ii) V= 12x2y  (area of cross-section into length) Area of cross section=area of triangle and length=y

now from the above eqn we know  y=200-24x2/ 10x

substitute this in V

12x2(200-24x2/ 10x)

this gives 240x-28.8x3




« Last Edit: May 11, 2010, 12:08:10 pm by nid404 »