Help ? ;) Using a directrix of y = -3 and a focus of (2, 1), what quadratic function is created?

f(x) = one eighth (x - 2)2 - 1

f(x) = -one eighth (x + 2)2 - 1

f(x) = one half (x - 2)2 + 1

f(x) = -one half (x + 2)2 - 1
Is it the 3rd one?

Question

Help ? ;) Using a directrix of y = -3 and a focus of (2, 1), what quadratic function is created?

 f(x) = one eighth (x - 2)2 - 1

 f(x) = -one eighth (x + 2)2 - 1

 f(x) = one half (x - 2)2 + 1

 f(x) = -one half (x + 2)2 - 1
Is it the 3rd one?

anonymous · Answer

@johnweldon1993

abb0t · Answer

where (h, k) are the coordinates of ur vertex.

abb0t · Answer

Use: $\sf \color{Red}{y = a(x - h)^² + k} $

anonymous · Answer

I can see what you put  @abb0t .. it says " math processing error"

anonymous · Answer

*cant

anonymous · Answer

@larryboxaplenty