Question

How to find the critical numbers and the open intervals on which the function is increasing or decreasing: √(49-x^2 )

Answer 1

get the first derivaitve and set it to zero

Answer 2

I got it to\[(49-x ^{2})^{1/2}\] but I'm seeing tips like use the product rule which would make it \[1/2(49-x ^{2})^{-1/2}+(49-x ^{2})^{1/2}\]. Do I need to do that second part or simply leave it at the first derivative and set to zero there?