March 20th, 2012, 10:47 PM  #1 
Member Joined: Feb 2012 Posts: 44 Thanks: 0  2nd, 3rd and 4th derivatives
My attempt at calculating these: a) d^2/(dx^2): ln(x+1) b) d^3/(dx^3): x^7 + 4x^6  x^2 c) d^2/(dx^2): 1/(x + 1) d) d^4/(dx^4): cos(2x) a) Product rule: 1/x(x + 1) + ln(1)= 1 + 1/x + ln Linearity rule: (1/x^2) + 1/x b) Linearity rule: 7x^6 + 6x^4  2x= 6(7x)^5 + 4(6x)^3  2= (5)(6)(7x)^4 + (3)(4)(6x)^2 = 210x^4 + 72x^2 c) Quotient rule: ((0)(x + 1)  (1)(1))/(x + 1)^2= 1/(x + 1)^2= ((0)(x+1)^2  (1)2(x + 1))/[(x + 1)^2]^2= (2x  2)/(x + 1)^4 d) the answer ends up being: cos(2x) + sin(2) I think Do these look valid? 
March 20th, 2012, 11:13 PM  #2 
Senior Member Joined: Jul 2010 From: St. Augustine, FL., U.S.A.'s oldest city Posts: 12,211 Thanks: 520 Math Focus: Calculus/ODEs  Re: 2nd, 3rd and 4th derivatives
a) b) c) d) 

Tags 
2nd, 3rd, 4th, derivatives 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Are partial derivatives the same as implicit derivatives?  johngalt47  Calculus  2  November 23rd, 2013 11:44 AM 
Please Help.. Derivatives dV/dR  dV/dt  fantom2012  Calculus  3  May 6th, 2012 07:53 PM 
DerivativesHelp  Arley  Calculus  5  April 13th, 2012 06:56 PM 
derivatives help  rsoy  Calculus  2  November 27th, 2010 08:26 AM 
derivatives  Calavan11  Calculus  2  December 11th, 2009 04:42 AM 