Square roots of numbers

Square roots of numbers

          It is customary not to write ‘+’ sign before a positive number. For example, +10 = 10. 

We shall, henceforth, observe this convention in all discussions.

6 ×  = 36     ∴ 6 is the square root of 36.

Similarly, (-6) × (-6) = 36       ∴ (-6) too is a square root of 36.

          
Thus, 6 and -6 are the two square roots of 36.

         

study the following video lessons:

 In the same way, work out in your mind the pairs of numbers of which 4, 49 and 121 are the squares and write statements like the above.

          What do we learn by observing the numbers and their square roots in the above examples?
we see that –

* Every positive number has two square roots.

* These square roots are opposite numbers of each other.