数学テスト

Square roots

√9 = ?

Square roots

The root of a number y is another number, which when multiplied by itself a given number of times, equals y. The second root (also called the square root) of 16 is 4:

$$16=4×4$$
We write this as:

$$√16=4$$
or
$$√^2{16}=4$$

For every even-degree root (2nd, 4th, 6th ....) there are two roots. This is because multiplying two positive or two negative numbers both produce a positive result. E.g:

$$4×4=16$$
$$(−4)×(−4)=16$$

Thus, $√^2{16}=±4$

The value inside the symbol √(called radical) is called radicand. For $√^3{27}$ 27 is radicand and 3 is the index.


   
   

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