Cartesian equations can be modified in order to seperate the x and y coordinates. This is achieved by using three variables.
Two equations that seperately define the x- and y- coordinates of a graph in terms of a third variable are called parametric equations.
Apply [a,b]: add a to the function for x and b to the function for y.
Stretch x-direction: multiply x function by required factor (similar for y -direction)
Reflect y-axis: multiply the x- function by -1; to reflect in the x-axis multiply the y - function by -1.