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: Dividing dy/dx by (dy/dx)^2

  1. Nov 12, 2011 #1
    1. The problem statement, all variables and given/known data
    Am I right to treat dy/dx as a fraction in this scenerio?

    2. Relevant equations

    3. The attempt at a solution

    [tex]= \frac{\frac{-dy}{dx}} {(\frac{dy}{dx})^2}[/tex]
    [tex]= \frac{\frac{-dy}{dx}} {\frac{dy}{dx} (\frac{dy}{dx})}[/tex]
    [tex]= \frac{1}{\frac{dy}{dx}}[/tex]

    Also, would we be able to multiple out dy/dx if we had for example:

    [tex] 2 = \frac{1}{\frac{dy}{dx}}[/tex]
    [tex] 2(\frac{dy}{dx}) = 1 [/tex]
  2. jcsd
  3. Nov 12, 2011 #2


    Staff: Mentor

    What happened to the minus sign?

    Note that you can simplify 1/(dy/dx).
    Sure. And if the goal is to solve for dy/dx, divide both sides of the last equation by 2.
  4. Nov 13, 2011 #3
    Simple mis-type.

    Like this?

    Which would read change of x with respect to y.. Hmm, I'm not used to it being like that.

    [tex]=\frac{dx}{dy} = lim_{Δx→0} \frac{Δx}{Δy}[/tex]
    [tex]= lim_{Δx→0} \frac{Δx}{f(x+Δx) - f(x)}[/tex]
    [tex]= f'(y)[/tex]

    Is what I stated correct?

    Oh okay, thank you! I just wanted to make sure I wasn't violating any rules here pertaining to derivatives.
    Last edited: Nov 13, 2011
  5. Nov 13, 2011 #4


    Staff: Mentor

    No, the limit would be as Δy→0. Here the assumption would be that x is some function of y.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Similar Threads for Dividing
Showing that one polynomial divides another