Question

y =4x^2+8x+5 ,find the focus ,directrix and vertex

Answer 1

y=4x^2-8x+5 = 4(x^2 -2x +1) -4 + 5

= 4(x-1)^2 + 1

OR y - 1 = 4(x-1)^2

Hence, the vertex of this parabola is (1,2) & cancave upward.