ChineseRemainder[{r_1, r_2, ...}, {m_1, m_2, ...}] gives the smallest non-negative x that satisfies all the integer congruences x mod m_i = r_i mod m_i.
ChiSquareDistribution[\[Nu]] represents a \[Chi]^2 distribution with \[Nu] degrees of freedom.
ChoiceButtons[] represents a pair of OK and Cancel buttons that close a dialog.ChoiceButtons[{act_ok, act_cancel}] represents OK and Cancel buttons that evaluate the ...
ChoiceDialog[expr] puts up a standard choice dialog that displays expr together with OK and Cancel buttons, and returns True if OK is clicked and False if Cancel is ...
CholeskyDecomposition[m] gives the Cholesky decomposition of a matrix m.
Chop
(Built-in Mathematica Symbol) Chop[expr] replaces approximate real numbers in expr that are close to zero by the exact integer 0.
CircleDot[x, y, ...] displays as x\[CircleDot]y\[CircleDot]....
CircleMinus[x, y] displays as x\[CircleMinus]y.
Circle
(Built-in Mathematica Symbol) Circle[{x, y}, r] is a two-dimensional graphics primitive that represents a circle of radius r centered at the point x, y. Circle[{x, y}] gives a circle of radius 1. ...
CirclePlus[x, y, ...] displays as x\[CirclePlus]y\[CirclePlus]....