Title 
Description 

Tangent 
A line that touches a function curve at a single point is said to be Tangent to the function. Tangent is also one of the six basic trigonometric functions; it is the ratio of the opposite side (from a specified angle) of a right triangle to the adjacent side.


Tangent Line 
A Line is said to be Tangent to a function when it touches the graph of the function at a single point.


Tau 
Tau is the 19th letter of the Greek alphabet.


Taylor Series 
Many common functions can be written as an expansion of the function about a point in a form known as a Taylor Series.


Term 
In most mathematical expressions a single Term is isolated from other Terms by plus or minus signs. A monomial is a Term.


Terminal Side of an Angle 
When in standard position, an Angle has an initial side, a ray on the positive xaxis, and a Terminal Side where the rotation of the angle stops, at an angle of specific measure (in degrees or radians).


Tessellate 
A planar pattern of repeating geometric shapes is a Tessellation; to produce these shapes is to Tessellate.


Tetrahedron 
A polyhedron with four faces.


Theorem 
A mathematical principle typically proved with some rigor is often a Theorem.


Theta 
The eighth letter of the Greek alphabet is Theta, a common variable for an angle.


Third Quartile 
For certain types of data, it is the 75th percentile. Also high quartile or upper quartile.


Three Dimensions 
The Dimensions of space or volume are Three Dimensions, typically labeled with rectangular, spherical, or cylindrical coordinates.


ThreeDimensional Coordinates 
ThreeDimensional Coordinates require an ordered triple to label a point in space.


Transcendental Number 
A Transcendental Number will not be the root of a polynomial with integer coefficients; it is an irrational number.


Transitive Property 
The Transitive Property is exhibited when three values are related in the following manner: If A = B and B = C, then A = C. The relation need not be equality.


Transpose (Matrix) 
When we interchange the rows and columns of a matrix we Transpose the Matrix.


Transversal 
A line that crosses two or more parallel lines is often termed a Transversal.


Trapezium 
In the United States, a quadrilateral with no parallel sides; in other Englishspeaking countries, what Americans term a trapezoid, a quadrilateral with one pair of parallel sides.


Trapezoid 
A quadrilateral with one pair of parallel sides (U.S.); the same figure is a trapezium in some other Englishspeaking countries. 

Trapezoidal Rule 
When approximating an integral in calculus we may treat each partition as a Trapezoid to determine the area under the curve.


Triangle 
A threesided polygon. Triangles are either acute, right, or obtuse.


Triangulation 
We may conduct geographic surveys or determine the altitude of various objects by a process termed Triangulation.


Trigonometric Identities 
The various statements in Trigonometry that are universally true, typically for any angle in the statement, are called Trigonometric Identities. For example, sin²x + cos²x = 1 for any angle x.


Trigonometry 
One of the more beautiful and elegant branches of mathematics, Trigonometry provides innumerable relationships built from similar (right) triangles.


Trinomial 
A polynomial with three terms.


Triple 
As a verb, Triple means to multiply by three. As a noun, the result from multiplication by three.


Triple Product (Scalar) 
Effectively, a Scalar Triple Product is akin to the determinant of a 3x3 matrix.


Truncation 
Replace the lesser digits of some number with zeros with no regard for rounding; this is Truncation.


Two Dimensions 
A plane has Two Dimensions. Planar figures are Two Dimensional.

