My Math Forum  

Go Back   My Math Forum > College Math Forum > Calculus

Calculus Calculus Math Forum


Reply
 
LinkBack Thread Tools Display Modes
March 20th, 2012, 11:47 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?
cacophonyjm is offline  
 
March 21st, 2012, 12:13 AM   #2
Senior Member
 
MarkFL's Avatar
 
Joined: Jul 2010
From: St. Augustine, FL., U.S.A.'s oldest city

Posts: 12,206
Thanks: 513

Math Focus: Calculus/ODEs
Re: 2nd, 3rd and 4th derivatives

a)

b)





c)

d)
MarkFL is offline  
Reply

  My Math Forum > College Math Forum > Calculus

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 12:44 PM
Please Help.. Derivatives dV/dR - dV/dt fantom2012 Calculus 3 May 6th, 2012 08:53 PM
Derivatives-Help Arley Calculus 5 April 13th, 2012 07:56 PM
derivatives help r-soy Calculus 2 November 27th, 2010 09:26 AM
derivatives Calavan11 Calculus 2 December 11th, 2009 05:42 AM





Copyright © 2018 My Math Forum. All rights reserved.