*5. Consider a renewal process having a gammaI mage interarrival distribution. That is, the interarrival density is Image

(a) Show that Image

(b) Show that Image whereI mage is the largest integer less than or equal toI mage.
Hint: Use the relationship between the gammaI mage distribution and the sum of r independent exponentials with rate λ to define in terms of a Poisson process with rate λ.