The law which asserts that the equation X = 0, complete or incomplete, can have no more real positive roots than it has changes of sign, and no more real negative roots than it has permanences of sign, was apparently known to Cardan; but a satisfactory statement is possibly due to Harriot (died 1621) and certainly to Descartes.


p.469 - History of Mathematics (1925) Vol.2

David Eugene Smith Quotes

The law which asserts that the equation X = 0, complete or incomplete, can have no more real positive roots than it has changes of sign, and no more...

The law which asserts that the equation X = 0, complete or incomplete, can have no more real positive roots than it has changes of sign, and no more...

The law which asserts that the equation X = 0, complete or incomplete, can have no more real positive roots than it has changes of sign, and no more...

The law which asserts that the equation X = 0, complete or incomplete, can have no more real positive roots than it has changes of sign, and no more...