I need help finding the vertex of the parabola y=x^2-3x-21
Y = X^2 =3X -21
V(h , k)
h = Xv = -b/2a = 3/2 = 1 1/2,
Substitute 3/2 for X in original Eq:
k = Yv = (3/2)^2 -3*3/2 -21 =
9/4 -9/2 -21 =
Find common denominator:
K = 9/4 -18/4 -81/4 = -93/4 = -23 1/4.
V(3/2 , -93/4).