2 Squares and Square Roots Squares Revision When
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2. Squares and Square Roots
Squares : Revision When a natural number is multiplied by itseif , the product obtained is called Squares : Revision For example , 5 x 5 = 25. Thus the square of 5 is 25. 5 x 5 is written as 52. 52 = 5 x 5= 25. Similarly , the square of 14 = 142 = 14 x 14 = 196.
Square of rational numbers As for natural numbers, when a rational number is multiplied by itself , the product obtained is called its square. study the following examples. (1) 352 = 35 x 35 = 1225 (2) (8/11)2=( 8/11) x (8/11)= 64/121.
we see from the above example that The square of a positive number is positive The square of a negative number too is positive (1) (5. 2 )2 =? (2)(6. 1)2 =(6. 1) x(6. 1) (5. 2 )2 = (5. 2) x (5. 2) = 37. 21 = 27. 04
The square root of rational number • To find the square root of rational number whose numerator and denominator are both perfect squares, we obtain a fraction as follows. In the numerator place, we put the square root of the numerator and in the denominator place, we put the square root of the denominator. The fraction thus obtained is the required square root
Examples 1) 4 25 4 x 4 = 2 25 x 25 5
Example • 1) 400 =400 x 400 = 20 • 49 49 x 49 7 • • 2) 100 =100 x 100 =10 • 121 x 121 11 •
Finding the square root of a perfect square by the division method • If the given number is very big it is tedious & timeconsuming to find its square root by the method of factorisation. •
Example • • • 1 + 1 20 + 0 201 + 1 202 1 01 10201 _1 002 _ 00 0201 00
