Title 
Description 

SAA Congruence 
SideAngleAngle Congruence establishes two congruent triangles.


Sample 
When we Sample a population we typically seek a representative Sample.


Sample Space 
We often use Sample Space to designate all the possibilities of potential outcomes for an event or process.


SAS Congruence 
SideAngleSide Congruence establishes Congruence between two triangles.


SAS Similarity 
SideAngleSide Similarity employs a fixed ratio between pairs of sides of triangles.


Scalar 
A value with unit of size (magnitude) and no direction is termed a Scalar. Contrast with a vector that has both magnitude and direction; a Scalar has magnitude but no direction.


Scalar Product 
A Product of vector multiplication, such as a dot product, that results in a value that is Scalar with size (magnitude) but no associated direction.


Scalene 
A triangle is considered Scalene if no two sides have the same length.


Scatterplot 
A planar plot of points from two variables with each point representative of a datum from both variables, most often with some relation or correlation.


Scientific Notation 
Scientific Notation is a way to easily represent values far from zero, in terms of powers of ten, either very large numbers or very small numbers; they are usually representative of physical quantities or values.


Secant 
The term applies to either a line containing the chord of a circle (or some other line segment between points on a function), or one of the six basic functions in trigonometry, the cofunction of the cosecant and the reciprocal of the cosine.


Second Derivative 
A Derivative taken of a first Derivative is termed a Second Derivative.


Second, Degree 
While "second degree" applies to a polynomial, a single Second with respect to Degree measure is onesixtieth of one minute, or one sixtieth of one sixtieth of one degree, or 1/1,296,000 of a revolution.


Second, Time 
One sixtieth of a minute, or 1/3600 of an hour, is one Second of Time.


Secondorder Differential Equation 
An ordinary Differential Equation in which the highest derivative is a second derivative is called a SecondOrder Differential Equation.


SecondOrder Polynomial 
A polynomial in which the highestorder term is of order two.


Sector 
A piece of a circle bounded by a central angle.


Segment, Circle 
A portion of a circle bounded by a chord and the circle itself.


Segment, Line 
A Line Segment is a set of collinear points bounded on both ends with, literally, endpoints.


Semicircle 
Half a circle; the portion of a circle on one side of a diameter.


Sequence 
Informally, any series is a Sequence. More formally, any series of terms that adheres or conforms to a pattern.


Series 
Most often a sequence of terms to be summed. Informally, any sequence of terms may be a Series.


Set 
Any collection of objects or values is considered a Set, whose cardinal number is the number of objects in the Set.


Set Intersection 
The Intersection of two (or more) Sets is the subset common to both (or all) Sets. Logically, the Intersection of two Sets A and B is literally the Set of "A and B." 

Set Union 
The Union of two (or more) Sets is the Set that contains both (or all) Sets. Logically, the Union of two Sets A and B is the Set of elements contained in either Set A or B, literally "A or B." 

Shell Method 
A method in calculus to calculate volumetric values from functions having been rotated about an axis.


Sigma 
The 18th letter of the Greek alphabet, uppercase sigma is used for summation notation, lowercase Sigma often denotes a standard deviation in statistics.


Sigma Notation 
Literally summation Notation, Sigma Notation employs an iterative mechanism around an uppercase Sigma to express the sum of a series or sequence of terms.


Significant Digits 
Informally, Digits that are not zero. Slightly more formally, nonzero Digits as well as zeros between nonzero Digits. Strictly, the number of Digits required to express a calculated value to within the reasonable tolerance or uncertainty of calculation.


Similar 
Geometrically, figures of like shape and proportions are said to be Similar.


Similarity 
Literally the quality of being Similar, which is to have the same shape and proportions, but not necessarily of the same size.


Simple Closed Curve 
A planar figure that neither crosses itself or contains a gap is a Simple Closed Curve; note that a curve can be "straight" according to the mathematicians.


Simple Harmonic Motion 
Periodic Motion with constant length of cycle time (a fixed period) is termed Simple Harmonic Motion.


Simplify 
When we Simplify mathematical expressions we restate them (or rewrite them) in more concise terms.


Simpson's Rule 
In calculus we may use three points of a parabola to approximate the function's range of values to determine the area of each partition of the integral.


Simultaneous Equations 
Equations with common solutions are Simultaneous Equations. Also, equivalent equalities (statements with equal signs) may be termed Simultaneous Equations.


Sine 
One of the six basic trig functions, in a right triangle the Sine of an angle is the ratio of the length of the opposite side to the length of the hypotenuse.


Singular Matrix 
A square Matrix with no inverse is termed a Singular Matrix.


Sinusoid 
A sine wave is called a Sinusoid; a cosine graph is also a Sinusoid.


Skew 
Lines neither intersecting nor parallel (noncoplanar lines) are termed Skew lines.


Slope 
A number associated with a line graphed in a plane, Slope is the ratio of rise over run, an indication of the steepness of the line. We may write a line as y = mx + b and use the value of m for Slope.


SlopeIntercept Equation of a Line 
The familiar y = mx + b, where m represents Slope and b is the yIntercept.


SOHCAHTOA 
A mnemonic device for remembering: sineoppositehypotenuse; cosineadjacenthypotenuse; tangentoppositeadjacent. Also stands for "some old hippie caught another hippie tripping on acid." 

Solid 
A threedimensional geometric figure or body that includes the interior region.


Solid of Revolution 
When a function is rotated around an axis (of Revolution) it generates a Solid of Revolution.


Solution 
Too often in math class, "the answer." More directly, a Solution is a value (or set of values) that makes a mathematical statement true.


Solution Set 
Strictly, any Solution is a Solution Set, the value(s) that make a mathematical statement true.


Speed 
A (typically fixed) ratio of length or distance to a unit of time; Speed is a scalar value, as in miles per hour (mph) or feet per second (fps).


Sphere 
A threedimensional figure comprised of points equidistant from a center point; a Sphere has a fixed radius.


Spherical Geometry 
Unlike plane Geometry, Spherical Geometry is not based on the parallel postulate. Many of our accepted geometric theorems, principles, and tenets (from plane Geometry) simply do not hold in Spherical Geometry.


Spherical Trigonometry 
Unlike plane Trigonometry, elementary Spherical Trigonometry is three dimensional. If based in spherical geometry, the math of Spherical Trig gets downright grisly.


Spheroid 
An oblate sphere. Sometimes, an ellipsoid.


Spiral 
Sometimes Spiral is used to describe a helix. A genuine Spiral is a plane figure of changing radius from a (usually fixed) origin.


Square 
One noun: the regular quadrilateral, equilateral and equiangular. Another noun: the result of multiplying a number times itself. Or, the verb: the operation of multiplying a number times itself, equivalently raising it to power two.


Square Matrix 
A Square Matrix has the same number of rows as columns.


Square Root 
Given a real value, the number that times itself (squared) produces the given value is its Square Root 

SSA Ambiguity 
SideSideAngle congruence is not enough to establish congruence between two triangles; it is the Ambiguous case.


SSS Congruence 
Two triangles whose corresponding sides are congruent are themselves congruent.


SSS Similarity 
When corresponding sides of two triangles are in a fixed ratio the triangles are similar.


Standard Equation of a Line 
When expressing the Equation of a Line with integral coefficients we may have the Standard Equation of a Line.


Standard Position 
An angle in Standard Position has been rotated counterclockwise (for positive rotation) from an initial ray on the positive xaxis.


StemandLeaf Plot 
A graphical device to group statistical data, typically by leading digits.


Step Function 
A discontinuous Function where the range jumps in increments (usually fixed) may be a Step Function.


Straight Angle 
An angle of 180 degrees or pi radians.


Strict Inequality 
A Strict Inequality does not include an "or equal to..." 

Subset 
Every set is a Subset of itself. A Subset has elements all contained in a "parent" set.


Subtraction 
The operation we begin thinking of as "take away" or "minus" is a way to find the difference between values.


Sum 
The result of addition.


Supplementary 
Supplementary angles sum to 180 degrees, or pi radians.


Symmetry 
Having a like but reversed profile or image (a mirror image) about a line is having the quality of Symmetry about the axis (of Symmetry).


Synthetic Division 
Synthetic Division is a technique to simplify the long division of polynomials.


System of Equations 
Most generally simultaneous Equations, or a set of Equations with identical variables.

