- #1
ilya.s
- 1
- 0
Hello everyone, this is an amazing forum! :)
I have a question: I have seen the formulas for focus/directrix of a parabola, but I cannot trust something unless I know how to get there.
How do I get the formulas of focus and directrix?
I got to an equation (X - Xf)^2 + (Y - Yf)^2 = (Y - Yd)^2 (distance between any point and focus equals to the distance between the same point and directrix). Where do I go from here?
Thank you!
I have a question: I have seen the formulas for focus/directrix of a parabola, but I cannot trust something unless I know how to get there.
How do I get the formulas of focus and directrix?
I got to an equation (X - Xf)^2 + (Y - Yf)^2 = (Y - Yd)^2 (distance between any point and focus equals to the distance between the same point and directrix). Where do I go from here?
Thank you!