What is the equation of the quadratic graph with a focus of (2, 0) and a directrix of y = −12?

f(x) = negative one twenty fourth x squared plus one sixth x minus thirty five sixths
f(x) = x2 − 4x − 35
f(x) = one twenty fourth x squared plus one sixth x plus thirty five sixths
f(x) = −x2 + 4x + 35

Question

What is the equation of the quadratic graph with a focus of (2, 0) and a directrix of y = −12?

 f(x) = negative one twenty fourth x squared plus one sixth x minus thirty five sixths
 f(x) = x2 − 4x − 35
 f(x) = one twenty fourth x squared plus one sixth x plus thirty five sixths
 f(x) = −x2 + 4x + 35

tkhunny · Answer

With the focus and directrix, you are perfectly set up to find the vertex.  Please draw the two you have and immediately locate the third piece.