Question

If (3, 6) is a point on the graph of y = f (x), which of the following points must be on the graph of y = - f (x)?
(a) (6, 3)       (b) (6, - 3)         (c) (3, - 6)          (d) (-3, 6)

Answer 1

Step 1:

The point is and the function is .

If is a function, then is reflection about the - axis.

If the point is on the graph of , then  must be on the graph of .

The point is on the graph of , then is on the graph of .

Thus the point is on the graph of .

Solution:

Option (c) is the correct choice.