Step-by-step explanation:
Use shifts to write sine and cosine in terms of each other.
a) sin (x – 5°) = cos (35°)
sin (x – 5°) = sin (90° – 35°)
sin (x – 5°) = sin (55°)
x – 5° = 55°
x = 60°
b) sin (2x – 17°) = cos (x – 4°)
sin (2x – 17°) = sin (90° – (x – 4°))
sin (2x – 17°) = sin (90° – x + 4°)
sin (2x – 17°) = sin (94° – x)
2x – 17° = 94° – x
3x = 111°
x = 37°
c) sin (x) = cos (x)
sin (x) = sin (90° – x)
x = 90° – x
2x = 90°
x = 45°
