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anonymous
 5 years ago
calculus question is there a typo here,
anonymous
 5 years ago
calculus question is there a typo here,

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anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0number 2, where it says then dz = f(z) du, shouldn't it say, then du = f(z) dz

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0that doesnt make sense

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0if u = sin z , right? then du = cos z dz ,

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0why would they ask that , that seems strange

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Not really, that's how I solve all my usubs.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0one sec, let me check

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0where exactly are you doing u substitution then

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0u = sin z , then du = cos z dz , so if dz = du/ cos z we have integral du/ u^4, oh the cos z cancels/

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0you might as well just substitute it directly

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0so you get integral du / u^4

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0this saves the step of having to plug that dz back in and then cancel, the whole point of u substitution i thought was to change the variables

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0\[u = sin\ z \implies du = (cos\ z)dz \implies dz = \frac{1}{cos\ z} du\] \[\implies \int \frac{cos\ z}{sin^4z}dz = \int \frac{cos\ z}{u^4}(\frac{1}{cos\ z})du\] \[ = \int \frac{1}{u^4} du \]

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Sometimes it works nicely, othertimes you have to do a bit of finagling.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I'm not sure what you mean by redundancy.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0its redundant, you can skip that step , ok because du = cos z dz, and you already have cos z dz in the numerator

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Sure, but sometimes it's not that obvious.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0i NEVER use this approach

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0give me problem and i will show yuo my approach

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I understand the other way, but too often it's just a matter of doing something in your head and I prefer to have it spelled out explicitly.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0hmmm, it seems odd , i guess i learned it a different way

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0everyone's brains work a little differently =)

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0well let me show you what i do, and you compare it with what you do

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0give me a problem, lets see

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0integral x e^(x^2) dx

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0u = x^2 , du = 2x dx , du/2 = x dx (its ok to divide out constant) so integral e^u du / 2

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0http://www.youtube.com/watch?v=Cj4y0EUlUY About different ways people think.
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