Show that (p-q) - (r-s) and (p r)- (g s) are not logically equivalent. the dual of a compound proposition that contains only the logical operators v, ^, and-is the compound proposition obtained by replacing each v by i, each ^ by v, each t by f, and each f by t. the dual of s is denoted by s*

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.