bitter yew
We got a formula for integration by parts. 1g is the question. I was looking at the answer and v' should be the differenciation of v right? lets say its swapped here and lets take v' as v and vice versa just for this context. How is differenciation of cos2x be (sin2x)/2? isnt it supposed to be -2sin2x?
zinc hullBOT
bitter yew
help
graceful hollow
From what I can tell, you are differentiating where you should be integrating
1/2 sin(2x) is the integral of cos(2x)
bitter yew
okay so i need to integrate v to get v' here right?
but in another example for v to v', they differenciated it here
how do i know if i should integrate or differenciate
graceful hollow
No they integrated
bitter yew
integration of sin is -cos how did they get cos
graceful hollow
So, when you are using integration by parts, you aren’t choosing u and v, you are choosing u and dv
In this case, they chose u=x and dv=cos(x)
bitter yew
So, when you are using integration by parts, you aren’t choosing u and v, you ar...
i thought it was the same
wait whats dv
bitter yew
okay so i need to integrate v to get v' here right?
but in another example for v...
the original question to this working is this btw
bitter yew
It’s the derivative of v
so v' is the derivative of v
graceful hollow
Yes
bitter yew
We got a formula for integration by parts. 1g is the question. I was looking at ...
but in this image, v' isnt the derivative of v though, its the integral
graceful hollow
When you use this method, you set one of your functions equal to u and the other equal to the derivative of some function v; then you have to integrate your derivative to find what v is
graceful hollow
but in this image, v' isnt the derivative of v though, its the integral
No, it is definitely the derivative
bitter yew
ohh wait my bad
graceful hollow
If you take the derivative of v then the 2 gets multiplied out to cancel the 1/2 and the sin(2x) becomes cos(2), leaving you with only cos(2x)
bitter yew
but in this image, v' isnt the derivative of v though, its the integral
the original question is integrate xcos2x
graceful hollow
Yeah
graceful hollow
Because they set cos(2x) equal to dv
When you use this method, you aren’t choosing u and v
You choose u and dv and you have to integrate dv to figure out what v is
graceful hollow
👍
bitter yew
but can i keep this channel open, because i might have some more questions