Results 1 to 2 of 2

Thread: Hyperbolic functions #2

  1. November 6th 2008, 09:59 AM #1
    jsu03
    jsu03 is offline
    Junior Member
    Joined
    Oct 2008
    Posts
    68

    Hyperbolic functions #2

    Calculate y' for:
    1. y= x sinh(x^2)
    I got to: y'= cosh x^2(2x) ....

    2. y= ln(cosh 3x)
    I got to: y= 1/cosh 3x (cosh 3x)
    = sinh 3/cosh 3x...
    I don't think these calculations are correct. Please help me. Thanks.
    Last edited by mr fantastic; October 5th 2009 at 03:30 AM. Reason: Re-titled post
    Follow Math Help Forum on Facebook and Google+
  2. November 6th 2008, 10:36 AM #2
    Soroban
    Soroban is offline
    Super Member
    Joined
    May 2006
    From
    Lexington, MA (USA)
    Posts
    11,242
    Thanks
    370
    Hello, jsu03!

    You are making really strange errors . . .

    1)\;\;y \:=\: x\cdot\sinh(x^2)
    Product Rule . . .

    y' \;=\;x\cdot\cosh(x^2)\cdot2x + 1\cdot\sinh(x^2) \;=\;2x^2\!\cdot\cosh(x^2) + \sinh(x^2)



    2)\;\;y \:=\: \ln(\cosh 3x)
    Chain Rule . . .

    y' \;=\;\frac{1}{\cosh3x}\cdot\sinh3x\cdot 3 \;=\;\frac{3\sinh3x}{\cosh3x} \;=\;3\tanh3x
    Follow Math Help Forum on Facebook and Google+
« Circular <-> Planar | directional derivatives!? »

Similar Math Help Forum Discussions

  1. Hyperbolic Functions
    Posted in the Calculus Forum
    Replies: 5
    Last Post: October 27th 2009, 06:50 PM
  2. Hyperbolic Functions #2
    Posted in the Calculus Forum
    Replies: 1
    Last Post: October 27th 2009, 06:38 AM
  3. Hyperbolic Functions
    Posted in the Calculus Forum
    Replies: 2
    Last Post: November 17th 2008, 05:31 AM
  4. hyperbolic functions!!
    Posted in the Calculus Forum
    Replies: 2
    Last Post: March 11th 2008, 10:29 AM
  5. hyperbolic functions
    Posted in the Calculus Forum
    Replies: 2
    Last Post: January 20th 2007, 02:40 PM

Search Tags


/mathhelpforum @mathhelpforum