11-14 Applications
Examine the inequality .4Xòì3X+5<.2X+4 graphically. Use the TEST functions to
explore the values of X where the inequality is true and where it is false.
1. Press 3. Select DOT, SIMUL, and the default mode
settings. Press 2 ", and turn off all stat plots.
2. Press (, and turn off all functions. Enter the left side of
the inequality as Y1, the right side as Y2, and the statement
of the inequality as Y3. Y3 evaluates to 1 if true and 0 if
false.
3. Press ), and enter these Window variable values.
Xmin=ë10 Ymin=ë10
Xmax=10 Ymax=10
Xscl=5 Yscl=5
4. Press +. Press 8 8 to move to Y3. Trace the
inequality, observing the value of X. Y3 is 1 when Y1 < Y2,
and Y3 is 0 when Y1 Y2.
5. Press ( and turn off Y1 and Y2. Enter equations to graph
only the inequality.
6. Press +. Notice that the values of Y3 and Y4 are zero
where the inequality is false.
Graphing Inequalities
Procedure