Practice problem
A parabola has focus (1,1)(1,1)(1,1) and directrix y=−1y = -1y=−1. What is the equation of this parabola?
y=12(x−1)2y=\frac{1}{2} (x-1)^2y=21(x−1)2
y=12x2y = \frac{1}{2} x^2y=21x2
y=(x2−1)2y = (\frac{x}{2}-1)^2y=(2x−1)2
y=14(x−1)2y = \frac{1}{4}(x-1)^2y=41(x−1)2
Type a concept, like “slope” or “photosynthesis”.