The set of all points in a plane the sum of whose distances from two fixed points is constant is​ a/an . The two fixed points are called the​ . The midpoint of the line segment connecting the two fixed points is the​ .

Adecibel is a logarithmic unit that can be used to measure the intensity of a sound. the function y = 10logx gives the intensity of a sound in decibels, where x is the ratio of the intensity of the sound to a reference intensity. the reference intensity is generally set at the threshold of hearing. use the graphing utility to graph the decibel function.a whisper has a sound intensity of 30 decibels. use your graph to you complete the following statement. the sound intensity of a whisper is times the reference intensity.