The arctangent is the inverse tangent function. Since. tan Ï/4 = tan 45Âº = 1. The arctangent of 1 is equal to the inverse tangent function of 1, which is equal to Ï/4 radians or 45 degrees: arctan 1 = tan-1 1 = Ï/4 rad = 45Âº. 1  Arctan.  Arctan calculator.
1 The difference is that an artery brings blood to the body and a vein takes blood to the lungs.  Arteries and Veins are part of the circulatory system, where arteries carry the blood from the heart to the organs, and the veins carry it from the organs to the heart again.
Arteries carry blood away from the heart, while veins carry blood towards the heart. Capillaries carry blood from arteries to veins. Arteries generally carry oxygenated blood from the heart to the tissues and organs during the systolic heartbeat cycle. They are under high pressure. (the only exception is the pulmonary arteries which carries deoxygenated blood from the heart to the lungs).