Cot theta-1/cot theta+1 = cos 2theta / 1+sin 2theta

Don't know how to find x given these segment lengths

Explain how you can find the missing fraction in 3 4/5 / (blank) 2 5/7. then find the missing fraction.

Afactory makes propeller drive shafts for ships. a quality assurance engineer at the factory needs to estimate the true mean length of the shafts. she randomly selects four drive shafts made at the factory, measures their lengths, and finds their sample mean to be 1000 mm. the lengths are known to follow a normal distribution whose standard deviation is 2 mm. calculate a 95% confidence interval for the true mean length of the shafts. input your answers for the margin of error, lower bound, and upper bound.