(ˈ)dā|kärts-, -kȧts-
Usage: usually capitalized D
Etymology: after René Descartes died 1650 French philosopher and mathematician
: a rule of algebra: in an algebraic equation with real coefficients, F( x ) = 0, arranged according to powers of x, the number of positive roots cannot exceed the number of variations in the signs of the coefficients of the various powers and the difference between the number of positive roots and the number of variations in the signs of the coefficients is even