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What is the
of 17,1 ? What is the square of ,085 ? What is the cube of 25,4 ? What is the biquadrate of 12? What is the square of 71?
Ans. 292,41 Ans..,007225 ins. 16387,064
EVOLUTION, OR EXTRACTION OF ROOTS. WHEN the root of any power is required, the business of finding it is called the Extraction of the Root.
The root is that number, which by a continual multipli. cation into itself, produces the given power.
Although there is no sumier but what will produce a perfect power by involution, yet there are many numbers of which precise roots can never be determined. But, by the help of decimals, we can approximate towards the 190t to any assigned degree of exactness.
The roots which approximate, are called surd roots, and those which are perfectly accurate are called rational roots,
1 Table of the Squares and Cubes of the nine digils. Hoots. *1|2|3| 41 51.61 7 | 1 81 9 Squares. |1|4| 9 | 16 | 25 | 36 49 64 81 Cubes. 1118 | 27 | 64 | 125 | 216 / 343. 512 | 729
EXTRACTION OF THE SQUARE ROOT. Any number multiplied into itself produces a square.
To extract the square root, is only to find a number, which being multiplied into itself, shall produce the giver number.
RULE. 1. Distinguish the given number into periods of two figures each, by putting a point over the place of units, another over the place of hundreds, and so on; and if there are decimals, point them in the same manner,
from units towards the right hand; which points show the number of figures the root will consist of..
2. Find the greatest square number in the first, or lem
land period, place the root of it at the right hand of the given number, (after the manner of a quotient in division) for the first figure of the rout, and the square number under the period, and subtract it therefrom, and to the remainder bring down the next period for a dividend.
S. Place the double of the root, already found, on the left hand of the dividend for a divisor.
4. Place such a figure at the right hand of the divisor, and also the same figure in the root, as when multiplied into the whole (increased divisor) the product shall be equal to, or the next less than the dividend, and it wilt be the second figure in the root.
5. Subtract the product from the dividend, and to the remainder join the next period for a new dividend.
6. Double the figures alreally found in the root, for a new divisor, and from these find the next figure in the root as last directed, and continue the operation in the same manner, til you have brought down all the periods.
Or; to facilitate the foregning Rule, when you have brought down a period, and a medl a dividend, in order to find a new figure in the root, you may livide said dividend, (omitting the right hand figure tiiereof,) by double the root already found, and the quotient will commonly be the figures sought, or being made less one or two, will generally give the next figure in the quotient.
1. Required the square root of 141225,64.
but when the periods belonging to any
leave a remainder, the operation may 469
be continued at pleasure, by annexing
periods of cyphers, &c. 145)4525
2. What is the square root of 1296 ? 3. Of
56644 ? 4. Of
5499025 ? 5. Of
36372961 ? 6. Of
184,2 ? 7. Of
9712,693809 ? 8. Of
0,45369 : 9. Of
,002916 : 10. Of
3 23 234 603 13,5 98,55
TO EXTRACT THE SQUARE ROOT OF
RULE. Reduce the fraction to its lowest terms for this and other roots; then
1. Extract the root of the numerator for the new num rator, and the root of the denominator, for a new denon nator.
2. If the fraction be a surd, reduce it to a decimal, a extract its root.
EXAMPLES. 1. What is the
155 SURDS. 6. What is the square root of
91287. What is the square root of ?
,77458. Required the square root of 361 ? 6,0207
APPLICATION AND USE OF THE SQUARE
ROOT. PROBLEM I. A certain General has an army of 518 how
many must he place in rank and file, to forn them into a square ?
V/5184572 Ans. PROB. II. A certain square pavement contains 20736 square stones, all of the same size; I demand how
many are contained in one of its sides? ✓20736=144 Ans.
PROB. III, To find a mean proportional between two
72x18=1296, and ✓1296=36 Ans PROB. IV. To form any body of soldiers so that they may be double, triple, &c. as many in rank as in file.
RULE. Extract the square root of 1-2, 1-3, Sic. of the given number of men, and that will be the number of men in file, which double, triple, &c. and the product will be the number in rank.
13122-2=6561, and 76561=81 in file, and 81%
PROB. V. Admit 10 hhds. of water are discharged through a leaden pipe of 24 inches in diameter, in a certäin time; I demand what the diameter of another pipe must be, to discharge four times as much water in the same time.
RULE. Square the given diameter, and multiply said square by the given proportion, and the square root of the pro. duct is the answer. 21-2,5, and 2,5X2,56,25 square.
4 given proportion.
/25,00<5 inch, dian, Ins.
PROB. VI. The sum of any two numbers, and their products being given, to find each number.
square of their sum, subtract 4 times their product, and extract the square root of the remainder, which will be the difference of the two numbers; then half the said difference added to half the sum, gives the greater of the two numbers, and the said half difference subtracted from the half sam, gives the lesser number.
The sum of two numbers is 43, and their product is 442; what are those two numbers ? The sum of the numb. 43x43=1849 square of de.
The product of do. 442x 4=1768 4 times the pro. Then to the sum of 21,5
✓81=9 dilfof the
EXTRACTION OF THE CUBE ROOT.
To extract the cube root, is to find a number, wlictr, being multiplied into its square, shall produce the given number.
RULE. 1. Separate the given number into periods of three figures each, by putting a point over the unit figure, and every third figure from the place of units to the left, and if there be decimals, to the right.
2. Find the greatest cube in the left hand period, and place its root in the quotient.
3. Subtract the cube thus found, from the said period, and to the remainder bring down the next period, calling this the dividend.
4. Multiply the square of the quotient by 300, calling it the divisor: