algebra
posted by sam on .
Find the line of symmetry, the maximum or minimum value of the quadratic function, and graph the function f(x)=2x^2+2x+9

Y = 2X^2 + 2X +9.
Vertex form: a( X  h)^2 + k.
h = Xv = b/2a = 2/4 = 1/2
k = Yv = 2(1/2)^2 + 2(1/2) + 9 = 19/2
V(h,k) = (1/2,19/2). a is negative; the
parabola opens downward. Therefore, the
vertex is a max. The line of symmetry is = h = 1/2.