1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Implicit differentiation find dy/dx and d2y/dx2

  1. Oct 11, 2009 #1

    find dy/dx and d2y/dx2

    I just want to make sure my answer is right and simplified

    I got dy/dx= (3-2y)/ (2x+2y)

    Now d2y/dx2 took some time but this is what i got:

    (-12x+2x2y+9+4yx-14y-4y^2) / ((x+y)(2x+2y)^2)
  2. jcsd
  3. Oct 11, 2009 #2
    Your dy/dx is correct. I didn't work out the second derivative, but as long as you took the derivative of dy/dx using the quotient rule and implicit differentiation, replacing dy/dx in that expression with what you found, and then simplifying correctly, then you did it right.
  4. Oct 11, 2009 #3
    yeah, i did that must i just wasn't to sure with my algebra (thats usually the step i would mess up). thanks though!
  5. Oct 12, 2009 #4
    I dont know if you can reduce this to a more simpler form but this is simplest i got: y"=(3-2y)(3+8x+6y)/8(x+y)^3
  6. Oct 12, 2009 #5
    was this from the equation i have up there or did u do this from the begining of the problem?
  7. Oct 14, 2009 #6
    the answer is yes and yes.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook