Analyzing two sinusoidal voltages on an oscilloscope with equal amplitude and period but different phases involves three steps. First, the peak-to-peak value is measured, which is twice the amplitude. Secondly, the period and angular frequency are determined. Third, voltage values for both sinusoids are measured at a fixed time to determine the phase angle, which depends on whether the sinusoid has a positive or negative slope. A graphical representation can be used to compare two sinusoids, where the horizontal axis represents the magnitude of cosine and the vertical axis represents the magnitude of sine. Similar to polar coordinates, the angles measured counterclockwise and clockwise from the horizontal axis are positive and negative, respectively. Subtracting 90 degrees from the argument of cosine yields the sine function. Two same-frequency sinusoids- one in sine and the other in cosine form, can be added using the graphical representation. The hypotenuse of the right-angled triangle represents the resultant sinusoid, and its argument measured from the horizontal axis equals the cosine inverse of the ratio of base and hypotenuse.