Question

Derive the equation of the parabola with a focus at (_5, 5) and a directrix of y = -1.

Answer 1

The answer is f(x) = one twelfth (x + 5)2 + 2, that is found when focus and  directrix of a parabola's formula is applied. 

Answer 2

Answer: Option D is correct.

Step-by-step explanation:

Since we have given that

focus = (-5,5)

and a directrix y= -1

Since, equation of parabola in this case will be

$(x-h)^2=4.a(y-k)$

Now, here

$y=k-a=-1\\\\\text { focus =(h,k+a)}\\\\\text{So,} k+a=5\\\\\text{ by solving these two equation , we get }\\\\a=3\text{ and } k=2$

So equation will be

$(x+5)^2=4\times 3(y-2)\\\\(x+5)^2=12(y-3)\\\\y=\frac{1}{12}(x+5)^2+2$

So, option D is correct .