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.
The difference between the blood vessels, arteries, veins and capillaries is in their shapes, sizes and function in the circulatory system.Blood vessels as defined by the dictionary as tubular structures carrying blood to tissues and organs of the body.he smallest arteries are called arterioles while the smallest veins are called the venules. The capillaries are connected to the arterioles and venules. It is important for the capillaries to be thin and small to be able to transfer of nutrients and other matters.