﻿ Polar Functions

# Polar Functions

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 Polar functions are entered in terms of r and θ. Because there is no θ key on a computer keyboard, the graph tool uses th to represent θ.   You can enter a normal polar equation such as r = 5 sin 3θ by typing   r = 5 sin 3th   or   5 sin 3th   The r = is optional and will be assumed if you do not enter it.     the graph tool can also draw inverse Polar functions - just enter them in terms of r.   th = 3r   th = 1/r   th = pi/4     As shown above, the graph tool can draw polar grids.  Go to the Grid page and check Polar Grid     Default Domains Cartesian and Inverse Cartesian functions have an "implied domain" - the bounds of the axes you have drawn the function on.  If you have not explicitly set a domain, the graph tool can automatically determine a suitable domain from the axes it is using.  For Polar graphs, there is not a natural domain that can be easily determined.  To counter this problem, the graph tool uses some default domains for polar graphs.   Polar graphs        0 ≤ θ ≤ 360 (degrees mode)          0 ≤ θ ≤ 2π (radian mode)   In most cases these default domains produce acceptable results.  Sometimes you may need to override the default domains in order to create the result you are after.