Page 12-19
We will try to plot the function f(θ) = 2(1-sin(θ)), as follows:
Θ First, make sure that your calculator’s angle measure is set to radians.
Θ Press „ô, simultaneously if in RPN mode, to access to the PLOT
SETUP window.
Θ Change
TYPE to Polar, by pressing @CHOOS ˜ @@@OK@@@.
Θ Press ˜ and type:
³2* „ Ü1-S~‚t @@@OK@@@.
Θ The cursor is now in the
Indep field. Press ³~‚t @@@OK@@@ to
change the independent variable to θ.
Θ Press L@@@OK@@@ to return to normal calculator display.
Θ Press „ò, simultaneously if in RPN mode, to access the PLOT
window (in this case it will be called PLOT –POLAR window).
Θ Change the H-VIEW range to –8 to 8, by using
8\@@@OK@@@8@@@OK@@@, and the V-VIEW range to -6 to 2 by using
6\@@@OK@@@2@@@OK@@@.
Θ Change the
Indep Low value to 0, and the High value to 6.28 (≈ 2π), by
using: 0@@@OK@@@ 6.28@@@OK@@@.
Θ Press @ERASE @DRAW to plot the function in polar coordinates. The result is a
curve shaped like a hearth. This curve is known as a cardiod (
cardios,
Greek for heart).
Θ Press @EDIT L @LABEL @MENU to see the graph with labels. Press L to
recover the menu. Press L @)PICT to recover the original graphics menu.
Θ Press @TRACE @x,y@ to trace the curve. The data shown at the bottom of the
display is the angle θ and the radius r, although the latter is labeled Y
(default name of dependent variable).
Note: the H-VIEW and V-VIEW determine the scales of the display
window only, and their ranges are not related to the range of values of
the independent variable in this case.