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 and veins are the parts of the circulatory system which carry blood between the heart, lungs, and all other areas of the body. While they both carry blood, they do not have much else in common. Arteries and veins are made of somewhat different tissue, each performing certain functions in a specialized way. The first and most important difference between the two is that all arteries carry blood away from the heart, and all veins carry blood to the heart from outlying areas.