+1 please add this

Agreed, I'm taking calculus 2 currently and I've found watching Khan's videos before I read the section helps me understand.

Almost 2 years later and we still do not discuss the root test :/

Chiming in 3 years later because this came up on Google when searched for the root test on KA. It's definitely still on the AP. Why the oversight? 

Not to sound ungrateful for everything KA provides for free. This was just a surprise.  

I was actually looking for a khan academy video specifically on root test and couldn't find it. It would be great if they could add it.

I watched the ratio test for Calculus 2 to learn. I google the root test for Khan Academy and found nothing but this post. I wish Khan Academy had a root test video. Khan Academy are very information and help me under the material!