Word  Definition  Examples  

Calculus  The study of infinitely small changes in slope and area,
used to solve complicated realworld problems that cannot be solved using
Algebra, Geometry, or Trigonometry.
Calculus was invented by several mathematicians at about the same time, but Sir Isaac Newton gets most of the credit. He needed calculus to be able to solve problems in astronomy and physics. 

Central angle  An angle whose vertex is the center of a circle.
The minor arc is the small part of the circle cut off by the angle, and the major arc is the larger part of the circle. 

Centroid  The point in a triangle where the medians of the triangle intersect. Click here for an animated example of the centroid.  
Central tendency  The tendency of data to be grouped near the center of the data.Measured using mean, median, and mode.  
Certain Event  An event whose probability is one (1) or 100%  Something that always happens  
Circle  The set of all points in a plane that are a constant distance of r
from a given point called the center.
On a coordinate graph (xy graph), if the center is at (h,k) and the radius is r, the equation of the circle is (xh)^{2} + (yk)^{2} = r^{2} (x2)^{2} + (y3)^{2} = 5^{2} is a circle with center at (2,3) and a radius of 5 

Circular function  The trig functions, because they can be defined as points along the radius of the unit circle.  
Circle Graph  A graph that represents the frequency of data as slices of a circle. The size of each slice
represents the frequency, usually recorded as a percent. Also know as a Pie Chart because of the shape. 

Circumcenter  The point in a triangle where the perpendicular bisectors of the sides of the triangle intersect. Click here for an animated example of the circumcenter.  
Closed interval  An interval that
includes both of its end points.
The example shows the closed interval from 3 to 1. 

Coefficient  The numerical factor when a term has a variable  a number that is multiplied by a variable in an equation or expression.  The number next to a letter  5y 5 is the coefficient and y is the variable 
Cofunction  In trigonometry, the function pairs: sine and cosine,
tangent and cotangent, and secant and cosecant. The graphs of cofunctions are closely related to each other. The example shows sin x and cos x on the same graph. 

Collinear  Points that lie on the same line  3 or more points that all line up
In the example, points A, B, C and D are collinear. 

Combination  An arrangement or listing where the order is not important.  Picking three students out of a classroom  
Common factors  Numbers, variables, and any products formed from the prime factors that appear in all terms of an expression  For 2x^{2} 6x 2 and x are the common factors because 2x times x equals 2x^{2} and 2x times 3 equals 6x 

Common logarithm  A base 10 logarithm, abbreviated log  By definition: log 1 = 0
log 10 = 1 log 100 = 2 

Commutative Property  Changing the order of addends or factors does not change the sum or product  Order doesn't matter when adding or multiplying  2 + 3 = 3 + 2 = 5
5 x 4 = 4 x 5 = 20 
Compass  A tool used in geometry to draw circles and parts of circles.  
Complementary angles  Two positive angles whose measures add to 90 degrees
If two angle A and B add up to 90 (A + B = 90°) then A and B are complimentary. 

Completing the Square  One method used to solve a quadratic equation. Other methods include factoring and the quadratic formula.  
Complex fraction  A fraction where the numerator, denominator, or both has a fraction  
Complex Number  A number of the form a + bi, where a and b are real numbers and i is the square root of 1.  Also called an imaginary number  
Concave polygon  When a diagonal contains points outside the polygon. An "innie" 

Congruent  Objects that are the same size and the same shape. The symbol for congruent is an equal sign with a squiggle over it.  
Conjecture  The conclusion reached in a math statement based on reasoning  a guess based on observations.  
Constant  A value or number that never changes  5 3.7 pi 

Constant Term  A term that has no variable factor  a number in an equation that is not multiplied by a variable  A number that stands alone  7x + 3 3 is the constant term 
Construction  Using only a compass and a straight edge to draw a geometric
figure. An excellent animated version of some common constructions is available at Math is Fun 

Continuous Data  Measures that change between data points  Things that could be measured at any time  they always exist  temperature, height, time, blood pressure, average grade 
Continuous Function  Function whose graph is an unbroken curve  it does not have any holes, gaps, or jumps
While this is apparently simple, it is mathematically hard to explain, requiring Calculus. For this detail, visit Wolfram Math World 

Convex polygon  No diagonal contains points outside the polygon  all the vertices of the angles point away from the center of the polygon.  
Coordinate of a point  On a number line, it is the distance of the point from the origin. On a coordinate axit is is the pair (x, y) that defines the location.  
Coordinate pair  A pair of numbers of the form (x, y) that gives the location of a point in the coordinate plane.  
Coordinate Plane  Formed when two number lines intersect at right angles. The xaxis is the horizontal axis and the yaxis is the vertical axis. The two axes meet at the origin (0,0). Click here for another explaination.  
Coplanar  Points and lines that are in the same plane The VLA west of Socorro, NM, is a group of 27 radio telescopes that are coplanar. To learn more about the VLA, visit the National Radio Astronomy Observatory web site. 

Correlation  A trend between two sets of data. A trend may show positive correlation (both sets of data get bigger together) negative correlation (one set of data gets bigger while the other gets smaller), or no correlation.  
Corresponding parts  Matching sides and angles in a polygon.  
Corollary  A statement that follows directly from a theorem.  Once you prove a theorem, the corollary is easily proven.  
Cosine  The ratio of the length of the side adjacent to an angle and the hypotenuse in a right triangle  side adjacent divided by hypotenuse  see Trigonometry 
Coterminal Angles  Two angles that share two sides in standard position.
In the example, 30, 330, and 390 are alll coterminal angles. 

Cubic Equation  An equation in the form ax^{3} + bx^{2} + cx + d = y, where a, b, c, and d are real numbers and a ≠ 0 
Largest exponent is 3  2x^{3 }+ 3x^{2} 5x + 7 = y 
Cycloid  A curve that represents a path traced by a fixed point on the circumference of a circle rolling along a line. Used in Trigonometry and Calculus.  x = at  a sin t y = a  a cos t for t any real number (usually time) 
Buttons created at ButtonGenerator.com.