Well I didn't bring home my notebook...so lets see what I can remember.
I know we talked about how if you have a definite integral with bounds that have an infinity in it. Also does this apply where you have a discontinuity or something? Well, anyways you replace it with an A or some other letter. Then I think you integrate normally..and then take the limit? I actually was confused on this last week. Can anyone give me an example or explain it better?
Well I will reexplain Lo'Hopital's Rule:
This is when you have a limit. You then plug in the number the limit is approaching into the equation. If you get anything like infinity/infinity, zero/zero, infinity/zero, zero/infinity you need Lo'Hopital's rule. So, you take derivative of the top and derivative of the bottom. Plug in the number from the limit. If you still get anything like infinity/infinity..etc. then you repeat this process. If not then you are done!
One last thing:
How do you know when something is to integrate with substitution?
Subscribe to:
Post Comments (Atom)
I know you shouldn't use substitution if you have like an x and an x^4 or something like that when it can't cancel.
ReplyDeleteAlso, you shouldn't use substitution when you ahve trig functions like sin cos in the same problem..
because they cancel..
whenever you have the derivative of something in your problem. or the derivative can be manipulated. like if you had x^2/x^3
ReplyDeleteyou'd use substituion and just put a 1/3 out front to be held accountable for that 3 you are missing.