A relation is a Function if and only if every input (x) maps to exactly ONE output (y).
Move the slider to test the boundary points of these relations. Watch the Vertical Line Test on the graph!
Mathematical Definition
x = 3.0
Output Calculation (y):
Testing...
Vertical Line Test
Rule 1: x²
Rule 2: 3x
* If the vertical dashed line intersects two DIFFERENT points at the same time, it is not a function.