pow - C++ Reference
https://www.cplusplus.com/reference/cmath/pow/
double pow (double base , double exponent) This function is also overloaded in <complex> and <valarray> (see complex pow and valarray pow).
PHP: pow - Manual
https://www.php.net/manual/ru/function.pow.php
You need to use this 'pow' function, there is no power operator. i.e. 3^2 means "3 XOR 2" not "3 squared". It is particular confusing as when doing Pythagoras theorem in a 'closet points' algorithm...
C library function - pow() - Tutorialspoint
https://www.tutorialspoint.com/c_standard_library/c_function_pow.htm
C library function - pow() - The C library function double pow(double x, double y) returns x raised to the power of y i.e. xy. Following is the declaration for pow() function.
std::pow, std::powf, std::powl - cppreference.com
https://en.cppreference.com/w/cpp/numeric/math/pow
pow. Trigonometric and hyperbolic functions. pow(±0, exp), where exp is negative, finite, and is an even integer or a non-integer, returns +∞ and raises FE_DIVBYZERO.