Find the general solution of each of the following equations:
(i) sec 3x = -2
(ii) cot 4x = -1
(iii)
To Find: General solution.
(i) Given: sec 3x = -2
We know that sec cos
= 1
So cos 3x =
Formula used: cos = cos
= 2n
, n
I
By using above formula, we have
cos 3x = = -cos
= cos
= cos
3x = 2n
x =
, n
I
So the general solution is x = , ,where n
I
(ii) Given: cot 4x = -1
We know that tan cot
= 1
So tan 4x = -1
Formula used: tan = tan
= n
, n
I
By using above formula, we have
tan 4x = -1= tan 4x = n
x =
, n
I
So general solution is x = (4n+3) ,where n
I
(iii) Given: cosec 3x =
We know that cosec sin
= 1
So sin 3x =
Formula used: sin = sin
= n
+ (-1)n.
, n
I
By using above formula, we have
sin 3x = = sin
3x= n
+
(-1)n .
x=
+
(-1)n .
, n
I
So general solution is x = +
(-1)n .
, where n
I