Answer:
in steps
Step-by-step explanation:
*The question did not specify what units are β, 10 and 70 (degree or radians)
based on sin A = cos (π/2 - A)
Sin(β – 10) = cos ( π/2 - (β – 10)) = Cos(5β + 70)
(1) π/2 - (β – 10) = 5β + 70 or (2) π/2 - (β – 10) = - (5β + 70)
if (1): π/2 - β + 10 = 5β + 70
6β = π/2 - 60
β = π/12 - 10 (answer depends the unit is degree or rads)
(π = 180°, 1 radian = 180°/π)
if (1): π/2 - β + 10 = - 5β - 70
4β = - π/2 - 80
β = - π/8 - 20 (answer depends the unit is degree or rads)
