IGCSE/GCSE/O & A Level/IB/University Student Forum
Qualification => Subject Doubts => GCE AS & A2 Level => Math => Topic started by: sabbath_92 on May 13, 2010, 05:30:49 pm
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Maths May 2005 Question 4.
It's not that tough though:
Here's the link:
http://www.freeexampapers.com/Dndex.php?d=QSBMZXZlbC9NYXRocy9DSUUvMjAwNSBKdW4=
Please show all the steps in (i).
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May 2005 Question 4.
It's not that tough though:
Here's the link:
http://www.freeexampapers.com/Dndex.php?d=QSBMZXZlbC9NYXRocy9DSUUvMjAwNSBKdW4=
Please show all the steps in (i).
which paper is the question in ?
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which paper is the question in ?
Paper 3. It's in the title.
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Paper 3. It's in the title.
paper 3 is practical isnt it???
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paper 3 is practical isnt it???
No you don't have practicals in maths.
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No you don't have practicals in maths.
oh crap i thought u were talkin about biology, hahahaha
srry my bad!!!
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oh crap i thought u were talkin about biology, hahahaha
srry my bad!!!
Lol it's aight. I hope I get the answer to the main question though.
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Lol it's aight. I hope I get the answer to the main question though.
srry i cant help i dont take math :(
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i. x=tan?
so dx/d?=sec^2?
dx=sec^2? d?
substitute it for dx in equation...the equation is
1_x^2/(1+x^2)^2 dx
whch becomes
1_tan^2?/(1+tan^2?)^2 sec^2 ?d?
then put in the identity fr 1+tan^2 ? as sec^2 ?
1-(sec^2?_1)/(sec^2?)^2 *sec^2 ? d?
then we get
2_sec^2?/sec^2? *d?
then
(2/sec^2?) _1 * d?
2cos^2? _1 d?
cos2? d?
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queston marks are for thetha
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i. x=tan?
so dx/d?=sec^2?
dx=sec^2? d?
substitute it for dx in equation...the equation is
1_x^2/(1+x^2)^2 dx
whch becomes
1_tan^2?/(1+tan^2?)^2 sec^2 ?d?
then put in the identity fr 1+tan^2 ? as sec^2 ?
1-(sec^2?_1)/(sec^2?)^2 *sec^2 ? d?
then we get
2_sec^2?/sec^2? *d?
then
(2/sec^2?) _1 * d?
2cos^2? _1 d?
cos2? d?
Thank you so much lol. I can imagine it was a pain writing all that down lol.
BUT, how do you get
(2/sec^2?) _1 * d?
from
2_sec^2?/sec^2? *d?
That was the part I was confused with when I first tried it.
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Nevermind I got it :-[lol
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2_sec^2 ?/sec^2? * d?
re arranging...
this is
(2/sec^2?)_(sec^2?/sec^2?) *d?
so it becomes
(2/sec^2?)_1
n den solve de rest
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These are the only identities that are needed for a2 right? Am I missing something?
tan(x y) = (tan x tan y) / (1 tan x tan y)
sin(2x) = 2 sin x cos x
cos(2x) = cos^2(x) - sin^2(x) = 2 cos^2(x) - 1 = 1 - 2 sin^2(x)
tan(2x) = 2 tan(x) / (1 - tan^2(x))
sin^2(x) = 1/2 - 1/2 cos(2x)
cos^2(x) = 1/2 + 1/2 cos(2x)
sin x - sin y = 2 sin( (x - y)/2 ) cos( (x + y)/2 )
cos x - cos y = -2 sin( (x - y)/2 ) sin( (x + y)/2 )
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identities r given in the mf9 fromulae sheet