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: Grade 12 Calculus, can someone pls, check for me?

  1. Dec 14, 2004 #1
    For both questions i have to find dy/dx
    1. y=x^5e^-3x

    I got (5x^4 e^-3x) + (x^5 (-3xe^-3x-1))

    some how that doesn't look right to me. not too sure...

    2.
    1-e^-x
    y= --------
    1+e^2x
    My answer was:


    (e^-x) - (1-e^-x) (2xe^2x-1)
    y'= -----------------------------
    1+e^2x


    Thanks for your help! It's much appreciated!
     
  2. jcsd
  3. Dec 14, 2004 #2

    dextercioby

    User Avatar
    Science Advisor
    Homework Helper

    1.It's wrong.It is an "x" too much.Figure out where. :wink:
    2.It's wrong.Again an "x" too much,a 'minus' missing,a whole term missing and a sqare on the denominator.Figure it out yourself.

    Daniel.
     
  4. Dec 14, 2004 #3
    First of all, thanks for replying, i'm still working on fixing the 2nd question, but i think i got the first one, the answer should be:


    y' = (5x^4 e^-3x) + (x^5 -3e^-3x)
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook