A straight line is tangent to a given curve at a point on the curve if the line passes through the point on the curve and has slope , where is the Derivative of .

**References**

Yates, R. C. ``Instantaneous Center of Rotation and the Construction of Some Tangents.''
*A Handbook on Curves and Their Properties.* Ann Arbor, MI: J. W. Edwards, pp. 119-122, 1952.

© 1996-9

1999-05-26