Need some help writting a formula for this conic section.
Given: Focus is (1,1) and directrix is y=-x-2
Thanks
You can use the distance formula and the formula for the distance from a point to a line.
$\displaystyle \sqrt{(x-1)^{2}+(x-1)^{2}}=\frac{|x+y+2|}{\sqrt{2}}$
Square both sides:
$\displaystyle 2(x-1)^{2}=\left(\frac{x+y+2}{\sqrt{2}}\right)^{2}$
Expand and simplify.
Anyone else for what? Show us what you have done after galactus' post. If you can't get any further than that point, let us know. Be specific!
-Dan
Edit: Actually a slight change is needed here:
$\displaystyle \sqrt{(x-1)^{2}+(x-1)^{2}}=\frac{|x+y+2|}{\sqrt{2}}$
should be
$\displaystyle \sqrt{(x-1)^{2}+(y-1)^{2}}=\frac{|x+y+2|}{\sqrt{2}}$
So
$\displaystyle (x - 1)^2 + (y - 1)^2 = \frac{(x + y + 2)^2}{2}$
-Dan