graphing

[haliebre]

I need help with graphing f(x) = -x2 + 6x - 8


Problem #2
Give the vertex for f(x) = 2x2 - 6x + 1



Problem # 3

Solve x-2/x+6 <= 0
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[Gene]

#1 Graphing is dificult here but if you start with dots at the vertex and x and y intercepts you are off to a good start. Then pick other x's as necessary to fill in gaps in the downward opening parabola...

#2 The vertex formula is
x=-b/2a from y=ax²+bx+c

#3 Multiply by x to get the "friendly" quadratic
x^2+6x-2 = 0
and find the x intercepts. That will give you two points of interest. The -2/x adds a third point (x=0), since it is undefined. Check an x in each of the four domains to see if it qualifies as a solution.