math using equation editor on microsoft word

this assignment is to be completed using microsoft word , in the word document you will solve the problems using the equation editor .

1.   Show, using algebra, that the formula  for a circle  is a special case of the formula  for an ellipse.

2.  Show, using algebra, that the formula for a parabola is a special case of the formula for an ellipse.

3.   In the context of a parabola, what is a focus?  What is a directrix?  What are the advantages of expressing the equation  of a parabola in focus-directrix form?

4.  What happens to the shape of a parabola, as the distance between  the vertex of the curve and the focus becomes very large?  Prove your answer using algebra.