cartesian coordinates: a system whereby points on a plane are identified by an ordered
pair of numbers, representing the distances to two or three perpendicular axes.
center: the point that is the same distance from all the points on a circle. The point that
is the same distance from all the points on a sphere. The point inside an ellipse
where the major and the minor axes intersect. The center of a circle that can be
inscribed in a regular polygon.
center of mass: centroid.
central angle: an angle that has its vertex at the center of a circle.
centroid: the center of mass of an object. The point where the object would balance if
supported by a single support. The point in a triangle where the three medians intersect.
chain rule: dy/dx = dy/du * du/dx.
chord: a line segment that connects two points on a curve.
circle: the set of points in a plane that are a fixed distance from a given point.
circular functions: same as trigonometric functions.
circumcenter: the point in a triangle that is the center of the circle that can be
circumscribed about the triangle. The intersection of the perpendicular
bisectors of the triangle.
circumference: the distance around a closed curve. The circumference of a circle is
2*pi*r where r is the radius of the circle.
circumscribed circle: a circle that passes through all of the vertices of a regular polygon.
closed interval: an interval that contains its endpoints.
coefficient: a constant that multiplies a variable. In Ax + By = C, A and B are coefficients
of x and y.
cofunction: the cofunction of a trigonometric function, f(x), is equal to f(pi/2 - x). The
cofunction of the sine is the cosine. The cofunction of the secant is the
cosecant. The cofunction of the tangent is the cotangent.
collinear: points are collinear if they lie on the same line.
commutative property: a + b = b + a. a*b = b*a.
complementary angles: two angles are complementary if their sum is 90 degrees.
completing the square: the method of adding an expression to both sides of an equation so
that one side becomes a perfect square trinomial.
complex fraction: a fraction that contains a fraction in its numerator and/or denominator.
complex number: the sum of an imaginary number and a real number written in the form
a + bi or r(cos x + isin x).
component: the components in the vector (a, b, c) are a, b, and c.
composite function: a function that consists of two functions arranged in such a way that
the output of one function becomes the input of the other function.
composite number: a natural number that is not prime.
concave: a figure is concave if a line segment can be drawn so that it goes in, out, then
back into the figure.
conclusion: the part of an if - then statement that follows the word "then". Consequent.
conditional statement: an if - then statement.
cone: the union of all line segments that connect a point and a closed curve in a different
plane from the point.
congruent: shapes or angles are congruent if you could put one on top of the other, and
they would look like just one shape. Equal.
conic section: parabola, hyperbola, ellipse, circle. Formed by the intersection of a plane
with a right circular cone.
conjecture: a statement that seems to be true, but has not yet been proven.
conjugate: the conjugate of a complex number is formed by reversing the sign on the
imaginary part of the number. The conjugate of a + bi is a - bi.
conjunction: a statement that is really two statements joined by the word AND. Both
parts must be true for the statement to be considered true.
consequent: the part of an "if - then" statement that follows the "then". Conclusion.
constant: a value that does not change.
continuous: a function is continuous if you can draw it without lifting your pencil off the
paper. y = f(x) is continuous at a if
1. f(a) exists.
2. lim as x-->a f(x) exists.
3. lim as x-->a of f(x) = f(a).
contrapositive: the contrapositive of A-->B is Not B---->Not A.
convergent series: an infinite series that has a finite sum is called convergent.
converse: the statement made by interchanging the hypothesis and the conclusion of a
convex: a set of points such that for any two points in the set, the line segment that
connects them is also in the set.
coordinates: a set of numbers that identifies the location of a point.
coplanar: points that lie within the same plane are called coplanar.
corollary: a statement that can be easily proven once a theorem is proved.
cosecant: csc x = 1/sin x
cosine: In a triangle, the cosine of an angle = (length of the adjacent side)/(hypotenuse)
cotangent: cot x = 1/tan x
coterminal angles: angles whose measures are 2kpi apart.
counting numbers: natural numbers. The numbers you use to count.
critical point: the point on a curve where the first derivative equals zero. Extremum.
cube: a solid figure with six square faces.
cubic: a polynomial of degree 3.
cylinder: the union of all line segments that connect corresponding points on congruent
circles in parallel planes.
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