text: /*"Point reflection" or "point symmetry" is a basic concept in geometry where a given point, P, at a given position relative to a mid-point, Q has a corresponding point,
  P1, which is the same distance from Q but in the opposite direction.
  
  Task
  Given two points P and Q, output the symmetric point of point P about Q. Each argument is a two-element array of integers representing the point's X and Y coordinates. 
  Output should be in the same format, giving the X and Y coordinates of point P1. You do not have to validate the input.*/
  
  
  //Quite simple once you understand what you need. Draw the points in a graph and it will be easier
  function symmetricPoint(p, q) {
    let r = []
    r[0] = (2*q[0]-p[0])
    
    r[1] = (2*q[1]-p[1])
    
    return [r[0],r[1]]
  }
  