Python has math library and has many functions regarding to it. One such function is
expm1(). This function mathematically computes the value of
exp(x) - 1. This method can be used if we need to compute this very value.
Syntax : math.expm1()
x : Number whose exp(x)-1 has to be computed.
Returns : Returns the computed value of “exp(x)-1”
Code #1 : Demonstrate the working of expm1()
The expm1 value using positive integer : 53.598150033144236 The expm1 value using negative integer : -0.950212931632136
There would be a question why
expm1() method was even created if we could always compute exp() and then subtract 1 from it. The first reason is that value
exp() - 1 is used a lot in mathematics and science applications and formulas.
The most important reason is that for smaller value of x, of the order less than e-10,
expm1() method give a result more accurate than
exp() - 1.
Code #2 : Comparing expm1() and exp()-1
The value with exp()-1 : 1.000000082740371e-10 The value with expm1() : 1.00000000005e-10