(a) Use cylindrical coordinates to show that the volume of the solid bounded above by the sphere r² + z² = a² and below by the cone z = r cot Φ₀ (or Φ = Φ₀), where 0 0

(b) Deduce that the volume of the spherical wedge given by

(c) Use the Mean Value Theorem to show that the volume in part (b) can be written as