What is the axis of symmetry and vertex for the graph #y=-2x^2+4x-6#?

Question

2672 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-06-30T08:35:37

the axis of symmetry is x=1; the vertex is (1,-4)

In the general equation

#y=ax^2+bx+c#

the axis of symmetry is given by

#x=-b/(2a)#

so, in this case, where a=-2 and b=4, it is:

#x=-4/-4=1#

This also is the x-coordinate of the vertex. To obtain the y-coordinate you can substitute the numeric value (x=1) in the given equation, so

#y=-2(1)^2+4(1)-6=-2+4-6=-4#