PLEASE HELP

The sinusoidal function f(x)=42sin(9x−π/10)+42 models the height, in centimeters, that a valve stem of the a tire is above ground x seconds after the tire begins to rotate.

How long does it take the valve stem to complete one revolution?

Enter your answer, rounded to the nearest hundredth of a second

The lengths of nails produced in a factory are normally distributed with a mean of 4.91 centimeters and a standard deviation of 0.05 centimeters. find the two lengths that separate the top 4% and the bottom 4%. these lengths could serve as limits used to identify which nails should be rejected. round your answer to the nearest hundredth, if necessary.

The formula for the lateral area of a right cone is la = rs, where r is the radius of the base and s is the slant height of the cone.which are equivalent equations?

Landon drove 103.5 miles on tuesday 320.75 miles on wednesday and 186.30 miles on thursday for work his company pays 0.07 $ for each mile he drives he expects to be paid more than $40,000 is he correct explain