Question

Calculate the value of A
1 . ( sin A -1) (2 cos A -1) = 0
2. ( tan A -1) ( cosec 3A -1 ) = 0

Answer 1

(1)
( sin A -1) (2 cos A -1) = 0
so
sinA-1=0
or, sinA=1
or, sinA=sin90
or, A=90 degree
And
2cosA-1=0
or, 2cosA=1
or, cosA=1/2
or cosA=cos60
or A=60 degree
so value of Ais 90 degree and 60 degree.
(2)
( tan A -1) ( cosec 3A -1 ) = 0
so
tanA-1=0
or tanA=1
or, tanA= tan45
or, A= 45 degree

And
cosec3A -1=0
or, cosec3A=1
or, cosec3A= cosec 90
or, 3A=90
or A=90/3
or, A=30 degree