Question 489785
I need help in finding the coordinates of the vertex for the parabola defined by the given quadratic function f(x) = -x^2 -4x + 8 


To find the axis of symmetry, or the x-coordinate of the vertex, we use the formula, {{{- b/2a}}}, where a = - 1, and b = - 4


That results in: x = {{{-((-4)/(2*-1))}}} = {{{-(-4)/-2}}} = - 2


Now, substituting - 2 for x in the equation, we get: f(x) or y = {{{-(- 2)^2 - 4(- 2) + 8}}} ------ f(x) or y = - 4 + 8 + 8 ----- y = 12


Since the x and y-coordinates are - 2, and 12, respectively, then the coordinates of the vertex of the parabola are ({{{highlight_green(- 2)}}}, {{{highlight_green(12)}}})


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