Mark the tick against the correct answer in the following:
To Find: The value of cos (2
)
Let , x = cos (2
)
x = cos (
+ 
)
Since we know that 
+ 
= 
+ 
= 
= 
x = cos (
)
Now , let y = 
tan y = 
By pythagorus theroem ,
(Hypotenuse )2 = (opposite side )2 + (adjacent side )2
Therefore, Hypotenuse = 5
cos (
)=cos y = 
1