Question

What is the range of the quadratic equation y= 2x^2 -8x +6?

1) range= y≥-8
2) range= y≤-8
3) range= y≤2
4) range= y≥2

Answer 1

find the second coordinate of the vertex. first coordinate is
\[-\frac{b}{2a}=-\frac{-8}{2\times 2}=2\]

Answer 2

oops

Answer 3

range=y>= -2

Answer 4

second coordinate is 8 - 16 + 6 = -2

Answer 5

\[y \ge -2\]\[[-2, \infty]\]

Answer 6

y=2x^2-8x+6=2(x^2-4x)+6=2(x^2-4x+4)+6-2(4)
=2(x-2)^2+6-8=2(x-2)^2-2

vertex is (2,-2)

parabola is concave up

[-2,inf)