Help its my birthday and im stuck on this question :D

Successful implementation of a new system is based on three independent modules. module 1 works properly with probability 0.96. for modules 2 and 3, these probabilities equal 0.95 and 0.90. compute the probability that at least one of these three modules fails to work properly.

Which of the following is the true for f(x) = 5cos

Over which interval is the graph of f(x) = x2 + 5x + 6 increasing?