Find the radius of a circle with a sector area of 9pi and a central angle of 90 degrees.

What is the difference between the points (4, 7) and (4, -5)? a. 0 units b. 2 units c. 4 units d. 12 units

Based on the figures as marked, /\rqs = —

On a string instrument, the length of a string varies inversely as the frequency of its vibrations. an 11-inch string has a frequency of 400 cylces per second. find the frequency of a 10-icnch string.