Find the general solution of each of the following equations:
(i) 
(ii) 
(iii) tan x = -1
To Find: General solution.
(i) Given: cos x = 
Formula used: cos = cos
 = cos = 2n
 = 2n , n
 , n I
 I
By using above formula, we have
cos x =  =
 =  cos(
cos( )= cos(
)= cos( )=cos(
)=cos( )
)  x = 2n
 x = 2n , n
 , n I
 I
So general solution is x = 2n where n
 where n I
 I
(ii) Given: cosec x = 
We know that cosec sin
 sin = 1
 = 1
So sinx = 
Formula used: sin = sin
 = sin = n
 = n + (-1)n
 + (-1)n , n
 , n
By using above formula, we have
sinx =  = sin
 = sin x = n
 x = n +
 + (-1)n.
(-1)n. 
So general solution is x = n +
 + (-1)n.
(-1)n.  where n
where n I
 I
(iii) Given: tan x = -1
Formula used: tan = tan
 = tan = n
 = n , n
 , n I
 I
By using above formula, we have
tan x = -1= tan x = n
 x = n , n
, n I
 I
So the general solution is x = n where n
where n I
 I