Suppose we want to choose 2 objects, without replacement, from the 4 objects pencil, eraser, desk, and chair

What is sin 7x/4 ? i need on this urgent trig

Find the roots of the equation below. x^2 - 6 + 9 = 0

Monitors manufactured by tsi electronics have life spans that have a normal distribution with a standard deviation of 1800 hours and a mean life span of 20,000 hours. if a monitor is selected at random, find the probability that the life span of the monitor will be more than 17,659 hours. round your answer to four decimal places.