Urgent solve please! The book is "Quantum Mechanics" by Liboff.
(15)
Let J1 and J2 be the respective angular momenta of the individual components of a two-component system. The total system has angular momentum J = J1 + J2. Show that:
(a) J1 • J2 = 1/2 [J1 + J2 - (J1 - J2)^2 + J1z • J2]
(b) J2 = J1 + J2 + 2J1 • J2 + J1 + J2 - (J1 - J2)^2