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.
There are two types of blood vessels: arteries and veins. Arteries carry blood under high pressure out to all areas of the body after being pumped by the heart. Veins carry blood that should be under low pressure, on its way back to the heart. An artery does not usually connect directly to a vein.Usually there are very small blood vessels called capillaries that connect an artery to a vein.. Source(s): http://www.hht.org/web/what_is_hht/overv...ere the blood in the capillaries gives oxygen to the cells and picks up the waste gas, carbon dioxide, from the cells. The capillaries are connected to the smallest veins in the body. The veins get bigger and bigger as they carry the blood back towards the heart.