Question

What's the vertex and axis of symmetry of y= -2x^2 + 8x-20

Answer 1

Answer:

Vertex

V  = (2, -12)

Axis of symmetry

x = 2

Step-by-step explanation:

To answer this question suppose the general equation of a parabola of the form:

$ax^2 + bx + c$

Where a, b and c are constants that belong to real numbers.

So it is known that the vertex of this parable is:

$x = \frac{-b}{2a}$

So, we use this same formula to find the vertex of the parabola $y = -2x^2 + 8x-20$

Where:

$a = -2\\b = 8\\c = -20\\\\x = \frac{-b}{2a}\\\\x = \frac{-8}{2 (-2)}\\\\x = 2$

The vertex of the parabola is at the point

V = (2, -12)

Finally, the axis of symmetry of a parabola always passes through its vertex. Then the axis of symmetry is the straight line

x = 2