4 A Treatise of Algebra.

Also the Mark ) is sometimes used as a Note of Divi-sion ; thus a -j- b)ab, denotes that the Quantity ab is to bedivided by the Quantity a-\-b ; and so of others. Butthe Division of algebraic Quantities is commonly, andmost commodiously exprefied by writing down the Di-visor under the Dividend with a Line between them

(in the Manner of Vulgar Fractions). Thus y repre-sents the Quantity arising by dividing c by b- t so that if

C Q "I - ff

c was i a and b 4., — would be r. Moreover -

T i 5 a — c

denotes the Quantity arising by dividing «-f- b by a — c ;

and ^ C the Quantity which arises by dividing

ab bb- f- cd by a-\-c. These Kind of Quantities arecalled algebraic F ractions; whereof the upper Part iscail’d the Numerator, and the lower the Denominator.

The Sign </, is used to express the Square Root of anyQuantity to which it is presix’d; As ^25 signifies theSquare R oot of 25 (which is because 5x5 =2 25).

And \/ °^ C —expresses the Square Root of

0 0

or of the Quantity which arises by dividing abc-\-aac bya - a ^ denotes the Square Root of °^

b. Also

considered as one Quantity ; but ^ 2 ~^ 2 ^ (because the

Line which separates the Numerator from the Denomi-nator is drawn below ^/) signifies that the Square Rootof the Quantity <z J -f- a z b must be first taken and thendivided by a 2 — b 1 : So that if a was 5 and b 4, then

A -j- a 2 b , , s/ct* -j ~a z b

would y/ - s~k i or;, but— 2 _jj- would

be only

— b*

or _L.

9 9

The same Mark with a Figure over it, is alsomade use of to express the Cube, or Biquadratick Root

of