Which of the following points does not lie on the graph of y=32x? (-1,-9) (1,9) (1/2,3)

The first thing we are going to do for this case is to rewrite the function.
 We have then:
 y = 3 ^ (2x)
 We evaluate the points:

 For (1,9):
 y = 3 ^ (2 * 1)
 y = 3 ^ (2)
 y = 9
 The point belongs to the function.

 For (1/2, 3):
 y = 3 ^ (2 * (1/2))
 y = 3 ^ (1)
 y = 3
 The point belongs to the function.

 For (-1, -9):
 y = 3 ^ (2 * (- 1))
 y = 3 ^ (- 2)
 y = 1/9
 The point does NOT belong to the function.

 
 The point (-1, -9) DOES NOT belong to the function.

Add up all the sides