Answer:
37) m∠x = 5.25
39) m∠x = 0.5236 and m∠x = 2.62
Explanation:
37)
∵ cotx = -0.6 and 3π/2 ≤ x ≤ 2π
∴ tanx = -1/0.6
∵ ∠ x in the fourth quadrant ⇒ ∴ m∠x = 2π - α where α is an acute angle
∵ tanα = 1/0.6 ⇒ α =

∴ α = 1.03038
∴ m∠x = 2π - 1.03038 = 5.25
39)
∵ cscx = 2 and 0 ≤ x ≤ 2π
∴ sinx = 1/2 ⇒ +ve value
∴ ∠x is in the first quadrant or the second quadrant
∴ m∠x = α or m∠x = π - α
∵ sinα = 1/2 ⇒ ∴ α =

∴ α = 0.5236
∴ m∠x = 0.5236
∴ m∠x = π - 0.5236 = 2.6216 ≅ 2.62