Graphical Solutions of Inequalities #2

[pr177]

Solve x^2-4x>21. Find the x-coordinates of the points of intersection when y1=x^2-4x and y2=21. Determine the interval(s) of x-values where the graph of y1=x^2-4x is above the line y2=21. What is the solution of the inequality?

 

[tkhunny]

That should work.

You may wish to be wary of the definition of "above". After formulating a theiry, try a point in the region and make sure.