Yes, equations don't exist in programming. Programming only has functions (~ formulas), no equations. An equation is handled by a human for solving. In the end, we don't want the equation. We only want to convert that equation into a formula for a subject. As the simplest example, to use the Pythagoras's theorem: Code: c^2 = a^2 + b^2 You have got c and a, and you want to find b. You don't try to write like this: PHP: $a ** 2 + $b ** 2 = $c ** 2; This is obviously syntax error, or if you are unlucky, unexpected behaviour is expected instead. You solve this equation by hand, making b the subject of the equation. Don't like pencil-and-paper calculation? Use Wolfram|Alpha. Wolfram|Alpha - solve a^2+b^2=c^2 for b We get: Code: b = +- sqrt( c^2 - a^2) (Seriously, do we even need to use a pencil or a computer to find this obvious solution? ) And obviously, we only want the positive solution. Therefore we can make such function: PHP: public function solveB($a, $c){ return sqrt($c ** 2 - $a ** 2);} The above is an introduction to using equations in programming. It can even grow more complex. For example, given a point, and we want to find its perpendicular distance from a line (defined by two points) (all three points indicated by position vectors): http://mathworld.wolfram.com/Point-LineDistance3-Dimensional.html The above link to Wolfram MathWorld shows how to evaluate the answer using vectors, and gave us a beautiful formula: So, we can create this function with vectors: (the Vector3 in PocketMine actually reflects the concept of vectors in the mathematical world) PHP: public function pointLineDistance(Vector3 $point, Vector3 $lineStart, Vector3 $lineEnd) : float{ return $point->subtract($lineStart)->cross($point->subtract($lineEnd))->length() / $lineEnd->subtract($lineStart)->length();} Note that the Vector3::cross() function used here is the cross product function in vectors, which is really useful if you know how to use it.