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A Glossary of Mathematical Terms - I

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Icosahedron

A 20-sided solid;, each face is in the shape of a triangle.

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Identity element

In operations (addition, multiplication, ...) the element that
is neitral as far as the outcome is concerned.

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Iff

If and only if.

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Imaginary number

A complex number with no real part.

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Improper fraction

See fraction.

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Improper subset

The null subset of a set or the whole set as a subset.

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Integer

A member of the set {0, +1, -1, +2, -2, ... }.

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Intercept

The point where a curve meets the *x*-axis
(*x*-intercept) or the *y*-axis
(*y*-intercept).

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Interior angles

Usually referred to the angles of a polygon.

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Intersection of sets

The set consisting of all elements that are common to two or
more sets.

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Interval

The set of all real (rational) numbers betwenn two fixed real
(rational) numbers.

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Isometry

A tarnsformation that keeps the same size and shape of figures.

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Isosceles

A polygon with two sides equal in length. Usually referred to
triangles and trapezoids.

copyright 2000 et seq. maddalena falanga & luciano battaia

first published on september 01 2003 - last updated on september 01
2003