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.
Arteries, on the other hand, are classified as systemic (part of the cardiovascular system), pulmonary (carry blood to the lungs), aorta and arterioles. Arteries carry bright red blood as it is oxygenated while veins have the dark red blood. Arteries progressively divide into smaller tubes unlike veins.
Arteries carry blood (with oxygen) from your heart out to your body, while veins carry blood (without oxygen) from your body to your heart. Arteries are strong, flexible blood vessels that are able to expand (get bigger) and contract (get smaller).They expand as your heart beats, and contract between heartbeats.rteries carry blood (with oxygen) from your heart out to your body, while veins carry blood (without oxygen) from your body to your heart. Arteries are strong, flexible blood vessels that are able to expand (get bigger) and contract (get smaller). They expand as your heart beats, and contract between heartbeats.