at the end of lecture 17, when talking about rotating around a point on circumference, Professor Aroux set the inner upper limit to be 2acos(angle), but why not just 2a?
Thanks

Question

at the end of lecture 17, when talking about rotating around a point on circumference, Professor Aroux set the inner upper limit to be 2acos(angle), but why not just 2a?
Thanks

anonymous · Answer

Because that limit is varying, as you can notice, when you take, for example, a/2 in the x axis, the distance between the origin and "r" is different than the distance when you take x=2a. |dw:1354775027342:dw|

anonymous · Answer

oh, thanks