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.
Difference between Artery and Vein. In closed circulatory system blood is circulated through closed vessels such as arteries, veins and capillaries. Arteries. All blood vessels leading from the heart are called arteries or the blood vessels which carry blood from the heart to various body organs are called arteries. All arteries carry oxygenated blood (pure blood) except pulmonary artery, which carries deoxygenated blood. The wall of the artery consists of three layers, namely tunica interna, tunica media and tunica externa. Veins. The vessels which carry blood from various body organs to the heart is known as veins.