Question

integration help

Answer 1

42! :P haha jk carry on

Answer 2

well i need to knw how to evaluate this case
\[\huge \int\limits \frac{(px+q)\;\;dx}{(ax^2+bx+c)}\]

Answer 3

im seeing partial fractions phooey

Answer 4

@dpaInc

Answer 5

@FoolForMath

Answer 6

u gt any specific examples? is lets say u diff the bottom and u get the top u can integrate to ln str 8 away

Answer 7

ya i was tlikung about that method

Answer 8

yep if not then use partial fractions or jus play around with it

Answer 9

if denominator factors, then yes use partial fractions
if it doesn't factor, i believe you need to use completing the square and trig sustitution

Answer 10

substitution**

Answer 11

@AravindG it's Rohangrr you wanna tag he's good with these stuffs :P

i agree with the @dumbcow :p

Answer 12

why do we differentiate denominator?

Answer 13

i mean my text book says by differentiating denominator we write numerator= A(2ax+b)+B

Answer 14

why do we do this? can anyone tell me the logic?

Answer 15

as in why we rewrite the numerator?

Answer 16

hehe ...i found the logic while i wrote tht ..it just struck me nw..to get differential of denominator in numerator!!

Answer 17

well does this ,ethod always work if we have the general case which i have written using eqn editor?

Answer 18

rules of integration

Answer 19

it always works as long as the differtiated denominator is the exact form of a mutiple of the numerator

Answer 20

or*

Answer 21

here is an example worked out by wolfram

http://www.wolframalpha.com/input/?i=integrate+%28x%2B3%29%2F%282x^2-x%2B5%29+dx

Answer 22

or a multiple*

Answer 23

"i mean my text book says by differentiating denominator we write numerator= A(2ax+b)+B"

This is definitely the best approach.

Answer 24

this method and partial fractions seem very similiar :)

Answer 25

A is straightforward, but you still need partial fractions for B.

Answer 26

why?