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neverforgetvivistee
can someone please help me in understanding graphing quadratic inequalities? look at this (answers are below) http://www.kutasoftware.com/FreeWorksheets/Alg1Worksheets/Graphing%20Quadratic%20Inequalities.pdf what does the solid/shaded line mean? Why is it shaded in and some are shaded out? I know how to get the coordinates by plugging in random x values, but I don't know about anything else.
ok, in general, lets say you have some function in the form:\[y=f(x)\]and you have some inequality like:\[y>=4\]
now, on the line \(y=f(x)\) you know the value of 'y' will EQUAL the value of 'f(x)', so we draw the curve for y=f(x) as a solid line to indicate that we need to include this region.
so now we need to consider the line y=4. this will be a horizontal line which passes through y=4.
the horizontal line could intersect the curve at some points. e.g.: |dw:1322436287068:dw|
now since our inequality is y>=4, we need to draw a solid line at the places where y=4.
but what about the shaded region?
sorry - my explanation went a bit hay wire above!
what I should have said is lets say we have an inequality of the form y>=f(x)
lol it's okay take your time :)
now, on the curve y=f(x), we know it satisfies the inequality - so we make the line solid
below the curve y=f(x) does NOT satisfy the inequality as there we have y<f(x)
above the curve y=f(x) DOES satisfy the inequality, so we include that region by shading it in
for shading it in, how do you know it satisfies the inequality?
does the diagram make sense?
not really :(
I have taken some point x=x1 (which is represented by the vertical line) where this vertical line crosses the curve y=f(x), we know y=f(x1) above that point of intersection, we know y>f(x1) below that point of intersection, we know y<f(x1)
np - sorry for the confusion at the beginning :-)