Here is the problem my Geometry textbook asks me to prove:
a tangent line of a parabola is a line that intersects but does not cross the parabola. Prove that a line tangent to the parabola x^2=4py at the point (a,b) crosses the y-axis at (0,-b).
From that I can draw the parabola up and down and the line on a given point (a,b) but really don't know how to start. Any help anyone could provide to help me get started would be appreciated.
a tangent line of a parabola is a line that intersects but does not cross the parabola. Prove that a line tangent to the parabola x^2=4py at the point (a,b) crosses the y-axis at (0,-b).
From that I can draw the parabola up and down and the line on a given point (a,b) but really don't know how to start. Any help anyone could provide to help me get started would be appreciated.