#please help with calc!

21 messages · Page 1 of 1 (latest)

orchid crown
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the problem is:

Show by implicit differentiation that the tangent to the ellipse x^2/a^2 + y^2/b^2 = 1 at the point (x_0, y_0) is x_0 x/a^2 + y_0y/b^2 = 1

i apologize for the horrible notation—i attached a photo if that helps

lapis arrow
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so which oart are you facing problem in

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find slope using implicit differentiation

orchid crown
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i understand how to differntiate it and everything, but i'm stuck making it look like the final thing. after i take the derivitive of the ellipse's equation and plug in x0 and y0 into my slope, then put it in point-slope form, i can't simplify it

lapis arrow
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then use point slope

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you get this

orchid crown
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well like yes

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but no 😭

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because i still can't simplify it properly

lapis arrow
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yes?

orchid crown
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ah you separated them

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ok i had them as a common denominator

lapis arrow
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you manipulate it to this form

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then observe that x0 and y0 lie on the ellipse

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so it should satisfy the equation

orchid crown
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thank you!

lapis arrow
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hence u can write rhs =1

orchid crown
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sorry for all that trouble just for the issue to be i didn't separate the fration

lapis arrow
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and you got your answer