Answer:
Yes, there exists one output for every input
Explanation:
* Lets revise how to test the function is one-one function
- Draw a horizontal line (parallel to x-axis) and moved it up and down
- If the horizontal line cut the graph in more than one point, then
the function is not one-one function
- If the horizontal line cut the graph in only one point, then the
function is one-one function
- That means one output for every input
* Now lets look to the graph
- If we draw a horizontal line and moved it up and down, the line
will cut the graph in just one point
- That means every x has different value of y
∴ There is no same y-coordinate for two x-coordinates
* Yes, there exists one output for every input