Nine of the built-in functions can be classified as arithmetic functions. Most of them take a numeric argument and return a numeric value. Table 9.1 summarizes these arithmetic functions.
|cos(x)||Returns cosine of x (x is in radians).|
|exp(x)||Returns e to the power x.|
|int(x)||Returns truncated value of x.|
|log(x)||Returns natural logarithm (base-e) of x.|
|sin(x)||Returns sine of x (x is in radians).|
|sqrt(x)||Returns square root of x.|
|atan2(y,x)||Returns arctangent of y/x in the range -π to π.|
|rand( )||Returns pseudo-random number r, where 0 <= r < 1.|
Establishes new seed for rand( ). If no seed is specified, uses time of day. Returns the old seed.
The trigonometric functions cos( ) and sin( ) work the same way, taking a single argument that is the size of an angle in radians and returning the cosine or sine for that angle. (To convert from degrees to radians, multiply the number by π/180.) The trigonometric function atan2( ) takes two arguments and returns the arctangent of their quotient. The expression
The function exp( ) uses the natural exponential, which is also known as base-e exponentiation. The expression
returns the natural number 2.71828, the base of the natural logarithms, referred to as e. Thus, exp(x) is e to the x-th power.
The log( ) function gives the inverse of the exp( ) function, the natural logarithm of x. The sqrt( ) function takes ...