Question

When a point lies on the x-axis, what do you know about its y-coordinate? When a point lies on the y-axis, what do you know about its x-coordinate?. .

Answer 1

When a point lies on the x-axis,the its y-coordinate=o
It shows that it is an x-intercept.
X-intercept is the point where the line or the grapg crosses the x-axis and thus the  value of y would be zero.Its also called the root of the function graphed.And they are denoted like this:
(x,0)

When a point lies on the y-axis,it is intersecting the y-axis and hence,called a y-intercept.It is the point where all the values of x are zero.And they are denoted like this:
(0,y)

Answer 2

When a point lies on the x-axis, y = 0, the coordinates are ( x , 0 ).
When a point lies on the y-axis, x = 0, the coordinates are ( 0, y ).