Why make this so complicated? Easier argument: let u=9-x^2. Then write x^3=x * x^2. x will disappear from du=-2x dx. Then you can solve for x^2 in u=9-x^2...
when you distributed the -243 you forgot to change the signs in the next step. You where saying it as you were doing it but didn't actually swap the signs in the step that followed
Instructive video, and I know that the main point is to show an example of trig substitution. For this problem however, it is a lot easier to use a normal u-substitution. Still, great videos as always!
OMG Thank You So much, I'm currently taking Calculus 2 and this video is about what I learn today :)
Thanks for uploading another one of these, i know this was complicated for me when i was in CalculusI
this is what you call together the TrU- substitution
great video sal. keep it up
But taking the square root of cos^2 θ yields |cosθ|, not cosθ. Wouldn't we have to make sure that the cosine is positive first?
you still got the right answer the only thing is the sign switch on the u sub expressions
Why make this so complicated? Easier argument: let u=9-x^2. Then write x^3=x * x^2. x will disappear from du=-2x dx. Then you can solve for x^2 in u=9-x^2...
Bro! You forgot to distribute the negative sign almost at the end!
can you tell what you using to create the video?
how did you created it the process i mean?
when you distributed the -243 you forgot to change the signs in the next step. You where saying it as you were doing it but didn't actually swap the signs in the step that followed
this is every case of "wdf"
Instructive video, and I know that the main point is to show an example of trig substitution. For this problem however, it is a lot easier to use a normal u-substitution. Still, great videos as always!
how would you use here normal u substitution?
Substitute u as the square root, and you will get - x^2 u^2 du. Remember that x^2 = 9 - u^2 and you now have a simple polynomial.
Great..!
I don't understand where sin comes from? And why don't you integrate by parts?
integral of ab =/= integral of a * integral of b
yeh the trig sub should be sec i dont get it either?