Question

The angle A lies in the third
quadrant and it satisfies the
equation 4 (sin?x + cosx)= 1.
What is the measure of the angle
A?​

Answer 1

Answer:

Since A lies in the third quadrant and cos A = −12, therefore, cos A = cos (180º + 60º) = cos 240º ⇒ A = 240º.