A cactus (plural: cacti, cactuses, or cactus) is a member of the plant family Cactaceae,[Note 1] a family comprising about 127 genera with some 1750 known species of the order Caryophyllales.
'cot' and 'crib' In British English, a cot is a bed for a baby. A cot has high sides to prevent the baby from falling out. In American English, a bed like this is called a crib.
In a right triangle, the cotangent of an angle is the length of the adjacent side divided by the length of the opposite side. In a formula, it is abbreviated to just 'cot'. Of the six possible trigonometric functions, cotangent, secant, and cosecant, are rarely used. In fact, most calculators have no button for them, and software function libraries do not include them. They can be easily replaced with derivations of the more common three: sin, cos and tan. Cotangent can be derived in two ways: The inverse cotangent function - arccot. For every trigonometry function such as cot, there is an inverse function that works in reverse. These inverse functions have the same name but with 'arc' in front. So the inverse of cot is arccot etc. When we see arccot A, we interpret it as the angle whose cotangent is A.