The expm1() function in D returns the mathematical raised to the power of a specific number minus 1. Here, Euler’s number, , is the base of the natural logarithm.
The mathematical representation of the expm1() function is shown below:
Note: We need to import
std.mathin our code to use theexpm1()function. We can import it using this:import std.math
expm1(number)
// number should be float, double or real.
This function requires a number as a parameter.
This function returns the mathematical raised to the power of number minus 1 sent as a parameter.
Note:
- If the parameter value is positive infinity,
expm1()returnspositive infinity.- If the parameter value is negative infinity,
expm1()returns-1.- If the parameter value is
NaN,expm1()returnsNaN.- If the parameter value is
-NaN, thenexpm1()returns-NaN.
import core.stdc.stdio;import std.stdio;//header required for functionimport std.math;int main(){//integerwriteln ("The value of expm1(10.0) : ",expm1(10.0));//positive double valuewriteln ("The value of expm1(2.56) : ",expm1(2.56));//negative double valuewriteln ("The value of expm1(-2.56) : ",expm1(-2.56));//zerowriteln ("The value of expm1(0.0) : ",expm1(0.0));//exceptional outputswriteln ("The value of expm1(real.infinity) : ",expm1(real.infinity));writeln ("The value of expm1(-real.infinity) : ",expm1(-real.infinity));writeln ("The value of expm1(real.nan) : ",expm1(real.nan));writeln ("The value of expm1(-real.nan) : ",expm1(-real.nan));return 0;}
Line 4: We add the header, std.math, required for the expm1() function.
Line 9: We use expm1() to calculate the integer value’s exponent minus 1.
Line 12: We use expm1() to calculate the positive double value’s exponent minus 1.
Line 15: We use expm1() to calculate the negative double value’s exponent minus 1.
Line 18: We use expm1() to calculate the zero’s exponent minus 1.
Line 20–26: We use expm1() to calculate the exceptional numbers’ exponent minus 1.