Given sin α = 12 / 13, α ∈ (π of 0,2), cos β = - 4 / 5, β ∈ (π of 2), find cos (α - β), sin (α - β)

Given sin α = 12 / 13, α ∈ (π of 0,2), cos β = - 4 / 5, β ∈ (π of 2), find cos (α - β), sin (α - β)

Because α ∈ (0, π / 2), cos α > 0. According to sin α = 12 / 13, cos α = 5 / 13
Similarly, sin β = 3 / 5
therefore
cos(α-β) = cosαcosβ + sinαsinβ = 5/13 * (-4/5) + 12/13 * 3/5 = 16/65
sin(α-β) = sinαcosβ - cosαsinβ = 12/13 * (-4/5) - 5/13 * 3/5 = -63/65
I hope it works