Register to reply

Another Deriv

by helpm3pl3ase
Tags: deriv
Share this thread:
helpm3pl3ase
#1
Nov1-06, 02:22 PM
P: 79
(sec4x + 4arctanx^2)=

(sec4x)(tan4x) + (4)(1/1+x^4)(2x).. Did I derive this correctly??
Phys.Org News Partner Science news on Phys.org
Bees able to spot which flowers offer best rewards before landing
Classic Lewis Carroll character inspires new ecological model
When cooperation counts: Researchers find sperm benefit from grouping together in mice
Office_Shredder
#2
Nov1-06, 02:33 PM
Emeritus
Sci Advisor
PF Gold
P: 4,500
Did you use the chain rule on the sec(4x) term?
courtrigrad
#3
Nov1-06, 02:45 PM
P: 1,237
you forgot to multiply by [tex] du = 4 [/tex] in the first term

helpm3pl3ase
#4
Nov1-06, 03:04 PM
P: 79
Another Deriv

(sec4x)(4)(tan4x)(4) + (4)(1/1+x^4)(2x)

or

16(sec4x)(tan4x) + (4)(1/1+x^4)(2x)??
helpm3pl3ase
#5
Nov1-06, 03:04 PM
P: 79
or do i keep just 1 4?? like this..

(sec4x)(tan4x)(4) + (4)(1/1+x^4)(2x)
Office_Shredder
#6
Nov1-06, 04:19 PM
Emeritus
Sci Advisor
PF Gold
P: 4,500
It would only be one four. Let sec(4x)=sec(u).

Then d(sec4x)/dx = d(secu)/dx = secu*tanu*du/dx

du/dx = 4, so

sec(4x)' = 4sec(4x)tan(4x)


Register to reply

Related Discussions
Calculating a deriv using logarithmic differentiation Calculus & Beyond Homework 1
Taylor series / 2nd deriv test Calculus & Beyond Homework 2
Deriv of trig function Calculus & Beyond Homework 4
Unsure on how to approach sin^4 Calculus 5
Deriv of xtanx Calculus 3