kmmollo9936 kmmollo9936 19-12-2022 Physics contestada Four waves are described by the following expressions, where distances are measured in meters and times in seconds. a. y = 0.12 cos ( 3x - 21t ) b. y = 0.15 sin (6x + 42t ) c. y = 0.13 cos (6x + 21t ) d. y = - 0.23 sin (3x - 42t )