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1st and 2nd Derivative

  • Thread starter JBD2
  • Start date
  • #1
61
0

Homework Statement


If x = cos(3t) and y = (sin(3t))² find dy/dx and d²y/dx².

Homework Equations


d/dx cosx = -sinx
d/dx sinx = cosx

The Attempt at a Solution


dx/dt = -3sin3t
dy/dt = 6sin3tcos3t

Not sure what to do now.
 

Answers and Replies

  • #2
Dick
Science Advisor
Homework Helper
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(dy/dt)/(dx/dt)=dy/dx, right?
 
  • #3
61
0
Yes, thank you. After I posted I wondered whether you could do that or not (a little unfamiliar with Leibniz notation) but it makes sense now thank you.
 

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