Page:The Algebra of Mohammed Ben Musa (1831).djvu/45

 In the same manner, if you require to triple the root of nine, you multiply three by three, and then by nine: the product is eighty-one; take its root, it is nine, which becomes equal to thrice the root of nine.

If you require to have the moiety of the root of nine. you multiply a half by a half, which gives a quarter, and then this by nine; the result is two and a quarter: take its root; it is one and a half, which is the moiety of the root of nine.

You proceed in this manner with every root, whether positive or negative, and whether known or unknown.

ON DIVISION.

If you will divide the root of nine by the root of four, you begin with dividing nine by four, which gives two and a quarter: the root of this is the number which you require—it is one and a half.

If you will divide the root of four by the root of nine, you divide four by nine; it is four-ninths of the unit: the root of this is two divided by three; namely, two-thirds of the unit.