Change the parameters of the parametric equations of the red ball below and click "(re)start".
Now check your conjectures by changing the parametric equations, e.g. x(t) = 8t and y(t) = 12t. Click "(re)start".
Now change the equations to linear form, e.g. x(t) = 10 + 8t and y(t) = 5 + 12t. Investigate other cases and make a conjecture. Can you deduce the cartesian equations? Describe your method ...
Try some quadratic and trigonometric equations ...