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.
Veins are blood vessels carrying blood towards the heart, whereas arteries bring blood away from heart. Mostly, arteries contain oxygenated blood, and veins contain carbon dâ¦ioxide-rich and oxygen-poor blood; however, there is one exception.
1 Only veins have valves. Arteries have a smaller lume. 2  An artery carries blood away from the heart, while veins transport blood to the heart.  The difference is that an artery brings blood to the body and a vein takes blood to the lungs.