pretty stuck on this one, any help apreciated:

the angular displacement (feta) of a shaft is given by feta= 1/2 (cos-5t. Find the velcoity of the shaft w at t= 2s

my apologies for the improper layout.

2 answers

Post what you have so far (:
Im afraid i don't even know where to get started. im new to my course and i havent studyied anything like this before.