The action potential is a sudden positive shift in the cardiomyocyte's cellular membrane potential, termed depolarization. Depolarization not only initiates contraction within the affected cardiomyocyte (Described in Cardiac Excitation-Contraction Coupling), but also initiates depolarization of adjacent cardiomyocytes.
Polar Coordinates The coordinate system which depicts the points from the pole to the certain distance at a particular angle is known as âpolar coordinatesâ. The positive horizontal axis in which that particular angle rotates is named as âpolar axisâ.
Now we can understand why we got the answer we did for the square root of i. It is easily seen that i forms an angle of 90 degrees with the real axis and has distance of 1 from the origin. Its square root is the number with a distance of 1 from the origin and an angle of 45 degrees from the real axis (which is ). A cautious reader will note that there is some ambiguity in choice of the angle in our definition of polar coordinates.