Calculus/differentiation (1 Viewer)

wandering17

Member
Joined
Sep 27, 2014
Messages
81
Gender
Female
HSC
2015
Hii's

can someone pls help me using the quotient rule, differentiate

-2x/(x^2+1)

this, and show working out pls?? i feel like im missing a step or something everytime i do it

thanks! much appreciated
 

Rhinoz8142

Well-Known Member
Joined
Jul 25, 2013
Messages
1,334
Location
Sydney
Gender
Male
HSC
2014
Uni Grad
2018
Hii's

can someone pls help me using the quotient rule, differentiate

-2x/(x^2+1)

this, and show working out pls?? i feel like im missing a step or something everytime i do it

thanks! much appreciated
this sis the quotient rule formulae..

(u.v')-(u".v)/ v^2

while

u/v

and there u go..
 

HeroicPandas

Heroic!
Joined
Mar 8, 2012
Messages
1,547
Gender
Male
HSC
2013
To do quotient rule the most efficiently is to not memorize the formula (well it is the same thing but you don't need to memorize letters)

Here's how I do it..

Step 1: Differentiate top times bottom, MINUS, differentiate bottom times top



Step 2: Draw the fraction bar under step 1



Step 3: Under the fraction bar, write the bottom all squared




Hope you understand :D
 
Last edited:

shreyansprasad

New Member
Joined
May 3, 2011
Messages
7
Gender
Male
HSC
2014
-2x/(x^2+1)

Let u=-2x

u'=-2

v=(x^2+1)

v'=2x

Formula= y'=(vu'-uv')/v^2

Hence y'=[(x^2+1)*(-2)-(-2x)(2x)]/(x^2+1)^2

y'=-2x^2-2+4x^2/(x^2+1)^2

y'=2(x^2-1)/(x^2+1)^2
:smile:
 

dan964

what
Joined
Jun 3, 2014
Messages
3,479
Location
South of here
Gender
Male
HSC
2014
Uni Grad
2019
The other method is to avoid quotient rule and to write it as


and then do the product rule which is easier to remember.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top