A relativistic positron \(e^{+}\)with kinetic energy \(T\) annihilates a stationary electron \(e^{-}\)and produces two photons \(e^{+}+e^{-} \rightarrow \gamma+\gamma\).

(a) At what angles are the photons emitted when they have equal energies?

(b) Is it possible for the photons to have unequal energies? Explain.