But if in the aforegoing Equation the Signs are alternately Affirmative and Negative; or which is the same thing if the Series be after this manner,
ny +
1 - nn / 2 × 3 ny3 +
1 - nn / 2 × 3 ×
9 - nn / 4 × 5 ny5 +
1 - nn / 2 × 3 ×
9 - nn / 4 × 5 ×
25 - nn / 6 × 7 ny7,
&c. = a.
The Root of it will be equal to
(1) y = ½
n√ a + √ aa - 1
+
½ /
n√ a + √ aa - 1
or,
(2) y = ½ n√ a + √ aa - 1