Write the equation of the directrix of the parabola shown below. Write your answer without using spaces. y^2 - 4x + 4y - 4= 0

y = - 3

Step-by-step explanation:

The general form of the equation of a parabola is given by:

with foci (h,k) and directrix equation given by y = k - p.

The parabola equation that you have is

you complete squares to get the general form of the equation:

Next, you compare the last expression with the general for of the equation of a parabola and you obtain:

hence, the directrix equation is y = k - p = - 2 - 1 = - 3