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!
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...
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
great video sal. keep it up
you still got the right answer the only thing is the sign switch on the u sub expressions
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?
can you tell what you using to create the video?
how did you created it the process i mean?
this is what you call together the TrU- substitution
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!
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.
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!
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?
this is every case of "wdf"