#Calc 2 Integration by parts

36 messages · Page 1 of 1 (latest)

stuck pilot
#

Having trouble with the 2nd integration part

grizzled daggerBOT
#
  1. Wait patiently for a helper to come along.
  2. Once someone helps you, say thank you and close the thread with:
+close
  1. Feel free to nominate the person for helper of the week in #helper-nominations
  2. Do not ping the mods, unless someone is breaking the rules.
  3. If you're happy with the help you got here, and the server overall, you can contribute financially as well:
tawny torrent
steady vale
#

use tabular integration

#

its so fire

stuck pilot
steady vale
#

Hallelujah

#

its basically just a way to set up integration by parts

#

it looks nice and is fast

#

lemme make a diagram

#

or not

#

so essentially you have two columns

#

u and v

#

u for differentiating and v for integrating

#

as for integration by parts, to determine what u and whats v, use liate (logs, inverse trig, algebra, trig, exponential) or lipet (logs, inverse, polynomial, exponential, trig)

#

whatever comes first is your u and other is v

#

here we have an exponential and a trig function, so we could do either, but importantly we should realize that these can be differentiated and integrated forever, but we can resolve this

#

so first we have
e^4x sin5x

#

differentiate left and integrate right

#

4e^4x. -1/5cos5x

#

nothing cancels out or is repeated so again

#

16e^4x. -1/25sin5x

#

and there we see we have the original * a coefficient

#

for tabular you take diagonal multiples in alternating signs

#

so we take the first e^4x and multiply by -1/5cos5x and leave it positive

#

then add the next diagonal: 4e^4x * -1/25sin5x but we multiply by -1

#

and lastly we can multiply across for 16e^4x * -1/25sin5x, but since its across its still in an integral

#

im rambling

#

do u wanna just hop in a vc and i can screenshare?

stuck pilot
#

ain't no way its that wasy

#

easy

steady vale
#

kinda we have to use a trick

stuck pilot
#

yeah im down for a vc

steady vale
#

ite im in general