Finding derivatives is actually really easy. There are just a few simple rules you have to apply deterministically to any problem, and the answer will pop out.
As I mention above, I bet they wouldn't be able to answer an even simpler question. Requiring application of product rule "raises the bar" a bit too high.
x^2 cos(x) + 2 x sin(x)
Finding derivatives is actually really easy. There are just a few simple rules you have to apply deterministically to any problem, and the answer will pop out.