Exponential and Logarithmic Functions

Exponential and Logarithmic Functions
exp()
double exp(double $dNumber)
This function returns the exponential of $dNumber. The domain of the function is (-∞, ∞) and the range is (0, ∞).
Argument	Description
double $dNumber	This is the independent variable value.
expm1()
double expm1(double $dNumber)
This function returns the exponential - 1 of $dNumber. This is computed in such a way that it is more accurate when $dNumber is close to zero. For the ordinary exponential function, these calculations can be inaccurate. The domain of the function is (-∞, ∞) and the range is (-1, ∞).
Argument	Description
double $dNumber	This is the independent variable value.
log()
double log(double $dNumber)
This function returns the natural log of $dNumber. The domain of the function is (0, ∞) and the range is (-∞, ∞).
Argument	Description
double $dNumber	This is the independent variable value.
log10()
double log10(double $dNumber)
This function returns the log base 10 of $dNumber. The domain of the function is (0, ∞) and the range is (-∞, ∞).
Argument	Description
double $dNumber	This is the independent variable value.
log1p()
double log1p(double $dNumber)
This function returns the natural log of $dNumber + 1. The function is more accurate than the normal log function, which becomes inaccurate near zero. The domain of the function is (-1, ∞) and the range is (-∞, ∞).
Argument	Description
double $dNumber	This is the independent variable value.
pow()
double pow(double $dBase, double $dExponent)
This function returns the value of $dBase raised to the power $dExponent: B^E. If the base and exponent are non-negative integers, the return value will be an integer.
Argument	Description
double $dBase	This is the value of the base.
double $dExponent	This is the value of the exponent.