Help, please, and thank you.

What basic trigonometric identity would you use to verify that csc x sec x cot x = csc^(2)x

Find the value of the variable and the length of each secant segment.

The number of revolutions of two pulleys is inversely proportional to their diameters. if a 24-inch diameter pulley making 400 revolutions per minute is belted to an 8-inch diameter pulley, find the number of revolutions per minute of the smaller pulley.