you have to find the derivative implicitly:
4x + y + x dy/dx - 12y² dy/dx = 0
4x+y = 12y² dy/dx - x dy/dx
4x + y = dy/dx (12y² - x)
dy/dx = (4x+y)/(12y²-x)
So the derivative, slope of tangent line, at (6,3) is
(4*6 + 3) / (108 - 6)
=27/102
= 9/34
2007-05-13 16:37:06
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answer #1
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answered by Kathleen K 7
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Let y' = dy / dx
Implicitly differentiate with respect to x:
2x^2+ xy – 4y^3 = -18
4x + xy' + y - 12y^2 y'= 0
Solve for y':
y'(x - 12y^2) = -4x - y
y' = (-4x - y) / (x - 12y^2)
Evaluate y' at (x, y) = (6, 3):
y' = (-4(6) - (3)) / ((6) -12(3)^2)
y' = -27 / (-102)
y' = 9 / 34
Answer: The slope of the tangent line to the curve 2x^2+1xy–4y^3=–18 at the point (6,3) is 9 / 34.
2007-05-13 23:51:07
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answer #2
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answered by mathjoe 3
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Hrmm.
Let's see if we can get the implicit derivative here...
2x^2+xy - 4y^3 =18
4x + y +xy' - 12y^2 y'= 0
x=6, y=3
24 + 3 + 6y' -108y' = 0
27 - 102y' = 0
-102y' = -27
y' = 27/102 = 9/34
That help?
I think I did that right.
2007-05-13 23:39:37
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answer #3
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answered by Roland A 3
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Implicit differentiation gives
4x + (y + x dy/dx) - 12y^2 dy/dx = 0
<=> dy/dx (x - 12y^2) + (4x + y) = 0
<=> dy/dx = -(4xy) / (x - 12y^2)
At the point (6, 3) we have
dy/dx = -(4.6.3) / (6 - 12.9) = 12/17.
2007-05-13 23:37:26
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answer #4
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answered by Scarlet Manuka 7
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