A piece of charcoal is found to contain
30% of the carbon 14 that it originally
had. When did the tree die from which the
charcoal came? use 5600 years as the
half-life of carbon 14.

Given (1+cosx)/(sinx) + (sinx)/(1+cosx) =4, find a numerical value of one trigonometric function of x. a. tanx=2 b. sinx=2 c. tanx=1/2 d. sinx=1/2

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

Two sides of a triangle mesure 20cm and 30cm. what is the measure of the third side