differentiate the both side!
1+y'=1/(1+y^2)y'
y'y^2/(1+y^2)=-1
y'=-1-1/y^2
2007-01-30 19:24:08
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answer #1
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answered by happyrabbit 2
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x + y = arctan(y)
You have to differentiate implicitly.
1 + y' = [1/(1 + y^2)] y'
Bring everything with a y' in it to the left hand side; everything else goes to the right hand side.
y' - y' [1 / (1 + y^2)] = -1
Factoring y' out of the left hand side, we get
y' (1 - [1 / (1 + y^2)]) = -1
Put the stuff in the brackets under a common denominator.
y' ( [(1 + y^2) - 1] / (1 + y^2) = -1
Simplify the numerator.
y' ( [y^2 / (1 + y^2)] ) = -1
Now, multiply both sides by the recipriocal of y^2 / (1 + y^2).
y' = (-1) (1 + y^2)/(y^2)
2007-01-31 02:55:46
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answer #2
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answered by Puggy 7
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I think you're asking for y', the derivative?
I suggest implicit differentiation:
1 + dy/dx = (1/(1+y^2))(dy/dx)
whence
y' (1/(1+y^2) - 1) = 1
and
y' = -(1+y^2)/y^2
= -1/(y^2) - 1
Alternatively, you could make it
tan(x+y) = y
Hence (sec(x+y))^2 (1 + y') = y'
and so on, but I think the first way is better.
2007-01-31 02:57:06
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answer #3
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answered by Hy 7
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x + y = arctan(y)
tan(x + y) = y
differentiate both side:
( 1 + dy/dx)/cos(x + y)^2 = dy/dx
1 + y' = cos(x + y)^2y'
y'(1 - cos(x + y)^2) + 1 = 0
y' = -1/sin(x + y)^2
2007-01-31 03:04:03
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answer #4
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answered by cp_exit_105 4
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You need to differentiate implicitly.
x + y = arctan y
1 + dy/dx = {1/(1 + y²)}(dy/dx)
1 = (dy/dx){1/(1 + y²) - 1} = (dy/dx){(1 - 1 - y²)/(1 + y²)}
1 = (dy/dx){-y²/(1 + y²)}
dy/dx = 1/{-y²/(1 + y²)} = (1 + y²)/(-y²) = -(1 + y²)/y²
2007-01-31 03:26:00
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answer #5
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answered by Northstar 7
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You cant. Whats x? You have 2 variables here. Do you want this in function of x? Add details, please
Ana
2007-01-31 02:42:45
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answer #6
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answered by MathTutor 6
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