Prove the identity: siny+tany/1+secy=siny

Asimple random sample of size nequals14 is drawn from a population that is normally distributed. the sample mean is found to be x overbar equals 70 and the sample standard deviation is found to be sequals13. construct a 90% confidence interval about the population mean

How do i solve uniform motion problems?

Look at triangle wxy what is the length (in centimeters) of the side wy of the triangle?