Answer:
59°, 239°
Step-by-step explanation:
cos(2x − 38) = sin(4x − 66)
Use phase shift.
sin(2x − 38 + 90) = sin(4x − 66)
The angles are equal, or a multiple of 360° apart.
2x − 38 + 90 = 4x − 66 + 360k
Solve for x.
118 − 360k = 2x
x = 59 − 180k
If k = 0, x = 59.
If k = -1, x = 239.
