Question

How to calculate this derivative?
http://i.imgur.com/iQGDeqO.png

Answer 1

You can either:
1) make the equation \[\frac{ t ^{2} +1}{ t ^{1/2}} \rightarrow t ^{-1/2}\times(t ^{2}+1)\]

Answer 2

distribute the t^-1/2...the use\[\frac{ d }{ dy}\left( a ^{n} \right)=na ^{n-1}\]

Answer 3

or you can use quotient rule

Answer 4

after you found the derivative, sub in r=4