sin a= 3/5, a lies in quadrant 1, and sin b = 5/13, b lies in quaternary 2, what is sin(a+b), cos(a+b), and tan(a+b)

Given a normal distribution with µ =50 and σ =4, what is the probability that 5% of the values are less than what x values? between what two x values (symmetrically distributed around the mean) are 95 % of the values? instructions: show all your work as to how you have reached your answer. don’t simply state the results. show graphs where necessary.