Y is inversely proportional to the square of x. A table of values for x and y is shown.

Х| 1 2 3 4
Y| 4 1 4/9 1/4

a) Express y in terms of x.
b) Work out the positive value of x when y = 25

Use the elimination method to find the solution to the system of equations. 2x - 3y = -9 -x + 3y = 6

The first-serve percentage of a tennis player in a match is normally distributed with a standard deviation of 4.3%. if a sample of 15 random matches of the player is taken, the mean first-serve percentage is found to be 26.4%. what is the margin of error of the sample mean? a. 0.086% b. 0.533% c. 1.11% d. 2.22%

Use the squared identities to simplify sin^2x cos^2x