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Revision as of 13:01, 24 February 2003 by Caid Raspa (talk | contribs)(diff) ← Previous revision | Latest revision (diff) | Newer revision → (diff)In mathematics, eccentricity is a parameter associated with every conic section. It can be thought of as a measure of how much the conic section deviates from being circular. In particular:
- The eccentricity of a circle is zero.
- The eccentricity of an ellipse is greater than zero and smaller than 1
- The eccentricity of a parabola is 1.
- The eccentricity of a hyperbola is greater than 1.
- The eccentricity of a straight line is infinity.
To calculate the eccentricity of any ellipse, measure the semi-major axis and call it a. Measure the semi-minor axis and call that measurement b. Now:
- eccentricity = e = √( 1 - b/a)
where √ is the square root sign. In astronomy, the eccentricity of an orbit can be calculated using this formula. For example, the eccentricity of the Earth's orbit is 0.0167.
In popular usage, eccentricity refers to unusual or odd behavior on the part of a person, as opposed to being normal.