Posted by Please Answer :) on .
if sin A= the square root of eleven over 7, find the value of cos 2A.

pleeaasee hellpp!! 
bobpursley,
Isn't cos2A= 12sin^2 A ?
Posted by Please Answer :) on .
if sin A= the square root of eleven over 7, find the value of cos 2A.
Isn't cos2A= 12sin^2 A ?