#### Sentence Examples

• The combination of rays is also sufficient in practice if the cardioid surface is replaced, by a spherical one.
• The polar equation to the cardioid is r=a(1-}-cos 0).
• The form of the limacon depends on the ratio of the two constants; if a be greater than b, the curve lies entirely outside the circle; if a equals b, it is known as a cardioid; if a is less than b, the curve has a node within the circle; the particular case when b= 2a is known as the trisectrix.
• The epicychid when the radii of the circles are equal is the cardioid (q.v), and the corresponding trochoidal curves are limacons.
• This may be readily accomplished geometrically or analytically, and it will be found that the envelope is a cardioid, i.e.