Answers

2016-03-04T12:15:02+05:30
The value of cos 2 is positive 
because angle 2 is first quadrant .
In first quadrant all the angles are positive.

0
But in book it is given negative in answers.
cos is an even function definitely i can say that it is positive.
suppose the question is - cos2 means its negative otherwise sure it is positive only.