Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 0 viewing
I just don't seem to be able to understand how to get the second derivative of a parametric equation. Can someone walk me through it?
 one year ago
 one year ago
I just don't seem to be able to understand how to get the second derivative of a parametric equation. Can someone walk me through it?
 one year ago
 one year ago

This Question is Closed

wcaprarBest ResponseYou've already chosen the best response.0
Okay, my parametric equation is x=3+3t^2, y+3t^2+t^3. to find dy/dx you divide (dy/dt)/(dx/dt). Which I can do no problem.
 one year ago

wcaprarBest ResponseYou've already chosen the best response.0
For the first derivative I got for 1((3t^2)/(4t)). Which the online homework problem says is correct.
 one year ago

wcaprarBest ResponseYou've already chosen the best response.0
To find the second derivative I have to find d/dt (dy/dx). I separated the two parts and got 0 for the one, of course, and then used the quotient rule on the 3t^2/4t part. Is this correct?
 one year ago

amistre64Best ResponseYou've already chosen the best response.1
a paramentric eqution is also a vector equation: r(t) = <x(t),y(t)> right?
 one year ago

amistre64Best ResponseYou've already chosen the best response.1
x=3+3t^2 , y=3t^2+t^3 x'=6t , y=6t+3t r'(t) = < 6t , 6t+3t^2 > which is what youve got for the tangent
 one year ago

wcaprarBest ResponseYou've already chosen the best response.0
Lol, I mixed two problems in what I explained, but yes, go on
 one year ago

amistre64Best ResponseYou've already chosen the best response.1
r''(t) is just the next derivative. r''(t) = <6, 6+6t> if im reading it right
 one year ago

amistre64Best ResponseYou've already chosen the best response.1
http://tutorial.math.lamar.edu/Classes/CalcII/ParaTangent.aspx might help
 one year ago

amistre64Best ResponseYou've already chosen the best response.1
bout 3/4 of the way down it goes into 2nd derivative
 one year ago

wcaprarBest ResponseYou've already chosen the best response.0
Right, but the question is asking for it in a certain form. Here is the question:
 one year ago

amistre64Best ResponseYou've already chosen the best response.1
you got that in a jpeg?
 one year ago

wcaprarBest ResponseYou've already chosen the best response.0
Lol, here it is in jpg
 one year ago

wcaprarBest ResponseYou've already chosen the best response.0
I just sliced a portion of the window to get the picture
 one year ago

amistre64Best ResponseYou've already chosen the best response.1
\[\frac{d^2y}{dx^2}=\frac{d}{dx}(\frac{dy}{dx})=\frac{\frac{d}{dt}(\frac{dy}{dx})}{\frac{dx}{dt}}\]
 one year ago

amistre64Best ResponseYou've already chosen the best response.1
soo dy/dx = 1+ t/2 stick this in the derivative thing for: 1/2 right?
 one year ago

amistre64Best ResponseYou've already chosen the best response.1
\[\frac{d}{dt}(\frac{dy}{dx})\to \frac{d}{dt}(1+t/2)\]
 one year ago

wcaprarBest ResponseYou've already chosen the best response.0
Yeah, you're right. But what I have is a dy/dx = 13t^2/4t
 one year ago

amistre64Best ResponseYou've already chosen the best response.1
or the right dy/dx .. lol
 one year ago

wcaprarBest ResponseYou've already chosen the best response.0
Sorry, I starting typing the first, which is pretty easy when I was actually going for a second problem. But this is the spot I always get confused. With that dy/dx I would lose the one and use quotient rule to solve for 3t^2/4t, wouldn't I? But when I do that it says I got the problem wrong
 one year ago

amistre64Best ResponseYou've already chosen the best response.1
reduce it by t and you got 3t/4 which is simpler to derive
 one year ago

amistre64Best ResponseYou've already chosen the best response.1
not reduce ..... simplify
 one year ago

wcaprarBest ResponseYou've already chosen the best response.0
Oh my Gosh!! I can't believe I wasn't seeing that! Thank you!
 one year ago
See more questions >>>
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.