Sharp EL-9450, Руководство по эксплуатации

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Chapter 4: Graphing Features
7. At the second line, press
C
to
clear any entries, then enter “3.5
+
1.2X” to represent the Orange Cab’s
fare system. When done entering
the equation, press
E
. The two
equations are now ready to graph.
8. Press
G
to draw the graphs.
To draw a graph, “=” must be highlighted. If not, move the
cursor to “=” of the targeted equation and press
E
to draw
a graph, and press
E
again not to draw a graph.
Graph Basics
The graph examples in this exercise are called X-Y graphs. An
X-Y graph is quite useful for clearly displaying the relationship
between two variables.
9. Let’s take a look at the graph. The
vertical axis represents the Y value,
while X is represented by the
horizontal axis. It appears that the
two diagonal lines cross at the point
where the X value is somewhere
between 2 and 3, indicating that Orange Cab costs less than
the other, after 3 miles of travelling.
10. Next, press
T
to find the values
per graph increment. When the
travelling distance is 2 miles, the
Tomato Cab charges 30 cents less
overall than the Orange Cab, but it
costs 30 cents more at 3 miles. To
make the X increment smaller, press
@
y
.
11. When the Table setting window
appears, move the cursor down to
“TBLStep”, type
. 5
, and
press
E
. Now the Y values will
be sampled at every 0.5 mile.
12. Press
T
to show the table
again. It indicates that when the X value is 2.5, both Y1 and Y2
values are 6.5. It is now clear that if you are travelling 2.5
miles or more, the Orange Cab costs less.