finding equation of the parabola?

Question

i am given the vertex of parabola as V(3,-1), axis parrallel to y-axis and the line y= - 4x+7 is a tangent to the parabola

how to find the equation

in (x-h)^2 = (y-k) form

Answer 1

(x-h)^2 = (y-k)

here vertex is (h, k)

in the given problem vertex is given as (sqrt(3), -1)

so h = sqrt(3) and k = -1

substituting these values in (x-h)^2 = y-k

[x - sqrt(3)]^2 = y-(-1)

[x - sqrt(3)]^2 = y +1

Answer 2

(x-3)^2 = y+1