What is the axis of symmetry and vertex for the graph #y = 3(x)^(2) - 7 x - 8#?

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Answer 1 · 2016-03-16T15:37:42

Show you a really cool trick for this
#x_("vertex")=7/6=" axis of symmetry"#
I will let you find #y_("vertex")#

Given:#" "y=3x^2-7x-8#

Factor out the 3 for the #x^2" and the "x" terms"#

#" "y=3(x^2-7/3x)-8#

Now apply #(-1/2) xx-7/3 = +7/6#

#x_("vertex")=7/6#

Axis of symmetry# -> x=7/6#

Just substitute #x=7/6# in the original equation to find #y_("vertex")#

Tony B