Conjectures on Parallel and Perpendicular Lines
Use the Show Object and Hide Object features to compare the various functions to f(x). Decide which ones are parallel to f(x) and make a conjecture on why they are parallel lines.
Now, use the Show and Hide Object Features to find which function is perpendicular to f(x). Come up with a conjecture on why these two functions are perpendicular.
Now, test this conjecture to find the last pair of functions that are also perpendicular!
(They are not necessarily perpendicular to f(x).)