Question

What is the x and y intercepts for x=3

Answer 1

Recognize that x=3 is the equation of a vertical line (which means this line is parallel to the y-axis).  The x-intercept is (3,0).  There is no y-intercept, because the graph does not cross the y-axis at all.

Answer 2

The x intercept is at 3, there is not y intercept and the slope is infinity.

Hope this helps :)