Which identity is not used in the proof of the identity 1 + cot^2 theata = csc^2 theata?

List the 10 possible samples (without replacement) of size 3 3 that can be obtained from the population of five officials.

Bob is putting books on a shelf and takes a break after filling 18 1/2 inches on the book shelf. the book shelf is now 2/3 full. how long is the entire bookshelf?

Solve the following inequalities and show the solution on a number line. 2x+3< 3(4x+5)