What is the value of a and b

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

Determine the mean and variance of the random variable with the following probability mass function. f(x)=( 729divided by 91) (1 divided by 9) superscript x baseline comma x equals 1,2,3 round your answers to three decimal places (e. g. 98.765).

What is the value of m in the equation 1/2 m - 3/4n=16 when n=8