#help me guys can anyone help me

44 messages · Page 1 of 1 (latest)

zenith wyvern
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find the second derivative of the given parametric equation: x = sin(2t), y = -cos(t) at the point t= π/6

flat monolithBOT
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old flare
zenith wyvern
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this is just the question

old flare
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Then most likely with respect to t

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So far what have you worked out?

zenith wyvern
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ive already did the derivative of both then turned it to dy/dx

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but im confused if i should enter the value of t or derive the dy again then input the value of t

zenith wyvern
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aight bro whats next

old flare
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I thought we just needed to take second derivatives of each component with respect to t

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But then you proceeded to look for d^2y/dx^2

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So I thought you knew better than I do

zenith wyvern
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i dont know what to do next bro

old flare
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I don't even know what a derivative of an equation is

zenith wyvern
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aight

lone carbon
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Can you post the actual question?

zenith wyvern
lone carbon
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Aaaah then I agree with rafain in that they want you to give the 2nd derivative wrt t

zenith wyvern
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i dont get the question too

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i mean i followed the rules then inserted the t after solving the parametric

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i got .250 then shit is wrong

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hahahaha

lone carbon
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How have you arrived at the first derivatives $\frac{dx}{dt}$ and $\frac{dy}{dt}$?

oblique thornBOT
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Lumberdude #LeaveWolfAsHeIs

zenith wyvern
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this is the part where im confused at

lone carbon
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So you took the first derivatives of both wrt t and then did the $\frac{dy}{dx}=\frac{\frac{dy}{dt}}{\frac{dx}{dt}}$?

oblique thornBOT
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Lumberdude #LeaveWolfAsHeIs

lone carbon
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And then you took the derivative of that monster wrt time?

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Why?

zenith wyvern
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thats parametric

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the format is d^2y/dx^2

lone carbon
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I know, but you're taking the derivative of $\frac{dy}{dx}$ wrt to time, why not do it the same way you got $\frac{dy}{dx}$ in order to get $\frac{d^2y}{dx^2}$?

oblique thornBOT
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Lumberdude #LeaveWolfAsHeIs

lone carbon
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I don't think what you're doing is entirely correct tbh

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If you've got $\frac{dy}{dx}$ the way to the second derivative would be to take the derivative wrt to x of this expression

oblique thornBOT
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Lumberdude #LeaveWolfAsHeIs

old flare
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It's basically $\frac{dy}{dx}=\frac{y'}{x'}$ and $\frac{d^2y}{dx^2} = \frac{\left(\frac{dy}{dx}\right)'}{x'}$

oblique thornBOT
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Rafain | #WhoIsWolf

old flare
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where the "primes" denote differentiation with respect to t

lone carbon
old flare
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I was mainly disapproving of the problem statement for being unclear

lone carbon
old flare