Suppose r varies directly as the square of m, and inversely as s. If r= 16 when m=9 and s = 9, find r when m=27 and s = 9.

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).

In a two-digit number the units' digit is 7 more than the tens' digit. the number with digits reversed is three times as large as the sum of the original number and the two digits. find the number.

The triangle shown has a hypotenuse with a length of 13 feet. the measure of angle a is 20 degrees. and the measure of angle b is 70 degrees. which of the following is closest to the length, in feet, of line segment ac? no need to use a calculator to find the trig numbers. each function is listed below. 4.4 5 12.2 35.7