Hazard rate in survival analysis using exponential distribution.

A function sometimes associated with a continuous nonnegative random variable is the failure rate (or hazard rate) function which is defined as
r (t) = f(t) / (1 - F(t))

For a density function f (t) with corresponding cdf F (t). This function has a number of different uses, particularly in survival analysis Derive r (t) for the case where T is an exponential distribution with parameter Beta.