Given :
An expression sin(140°)cos(20°) – cos(140°)sin(20°) .
To Find :
The value of given expression .
Solution :
We know ,
sin(A - B) = sin A cos B - cos A sin B
By comparing with above formula , we get :
A = 140° and B = 20° .
So , sin(140°)cos(20°) – cos(140°)sin(20°) = sin ( 140°- 20°) = sin 120° .
Now , [tex]sin 120^\circ{} = \dfrac{\sqrt{3}}{2}[/tex]
Therefore , the value of expression is [tex]\dfrac{\sqrt{3}}{2}[/tex] .
Hence , this is the required solution .
