Answer:
Sin theta = -1/2
Step-by-step explanation:
pi < =theta <= (3pi)/2.
The above expression shows we are dealing with angle on the 3rd quadrant.
I.e greater than 180 but less than 270.
So sin tita = (√3)/2
But sin and cos are all negative in the third quadrant.
So tita = sin^-1(√3)/2
tita = 60°
Cos tita = cos 60
Cos tita = cos 60
Cos60 = 0.5
Cos 60 = 1/2
If
sin theta = -(sqrt(3))/2
Sin theta = -1/2