Let u = sinx.
Then du = cosx dx.
So it's the same as integrating u...you get:
∫ sinx (cos x dx) = ∫ u du = 1/2 u² + C = 1/2 (sin²x) + C
2007-01-20 01:09:05
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answer #1
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answered by Jim Burnell 6
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Ok let it be simple like this
no need to put U as a substitution since its simple in this and can be solved without any substitution
sin2x=2sinxcosx
sin2x/2=sinxcosx
integration of sin2x/2 dx=integration of sin2x/2
answer is (-cos2x/4)+c
now if this is wht u wanted please choose it as the best answer
2007-01-20 09:24:35
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answer #2
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answered by SOAD_ROX 2
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sin(x)cos(x) = 1/2sin(2x)
integral of 1/2sin2x = -1/4cos(2x)
Note: my answer and Jim's are the same - remember there is an additive constant.
-1/4cos(2x) + C = 1/4(sin^2x - cos^2x) + C
let C = 1/4 = 1/4(cos^2x + sin^2x), then
1/4(sin^2x - cos^2x) + 1/4(cos^2x + sin^2x) = 1/2sin^2x
2007-01-20 09:16:50
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answer #3
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answered by sofarsogood 5
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2sin(x)cos(x) = sin(2x)
sin(x)cos(x) = 0.5sin(2x)
Integrate sin(x)cos(x) = -2(0.5)cos(x) + c
= -cos(x) + c, where c is an arbitary constant
2007-01-20 11:38:30
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answer #4
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answered by lwyenin 2
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1/2 sin^2(x)..............i really dont''t know how to explain, but this is the answer
2007-01-20 09:39:44
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answer #5
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answered by fierceyeo 1
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