What is the axis of symmetry and vertex for the graph # y-8=-2(x-3)^2#?

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Answer 1 · 2017-01-09T19:05:05

See explanation

#color(brown)("There is a shortcut to this that is part of completing the square")#

You need the form of #y=ax^2+bx+c#

#x_("vertex")=(-1/2)xxb/a -> "axis of symmetry"#

Given:#" "y-8=-2(x-3)^2#

#=> y=-2(x^2-6x+9)+8#

#=>y=-2x^2+12x-10 #

so #x_("vertex")=(-1/2)xx12/(-2) =+3#

Tony B