Question

if α and β are acute angles satisfying sinα = 1/2, cosβ = 1/3 , then α+β∈ to

Answer 1

sin(α+β) = sinαcosβ + cosαsinβ 
             = (1/2×1/3) + (√3/2 × 2√2/3)
             = 1/6 + √(2/3)
so (α+β) = sin⁻¹ (1/6 + √(2/3))