Polar Coordinates

In polar coordinates, you specify a point P by giving the angle θ that the ray from the origin to the point P makes with the polar axis and the distance r from the origin. The equations that relate rectangular coordinates to polar coordinates are given by

x = r cosθ,        y = r sinθ

or equivalently,

x2 + y2 = r2,        tanθ = $\displaystyle {\dfrac{{y}}{{x}}}$

$\blacktriangleright$ To make a plot in polar coordinates

1.
Type an expression for the radius in terms of the angle θ.

2.
With the insertion point in the expression,from the Plot 2D submenu choose Polar.


To obtain the view shown in the following two plots, select the frame and choose Edit + Properties. Click the Axes tab, check Equal Scaling on Both Axes, and choose OK.

$\blacktriangleright$ Plot 2D + Polar

sin 2θ

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$\blacktriangleright$ Plot 2D + Polar

1 - cosθ

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$\blacktriangleright$ Plot 2D + Polar

1 - sinθ +2 sin 3θ

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