First, let's take an example to show that sqrt{a^(2)} is not equal to a. Suppose a = -3, then:
sqrt{a^(2)} = sqrt{(-3)^(2)} = sqrt{9} = 3
But a = -3, so sqrt{a^(2)} is not equal to a.
Now, let's move on to explain why sqrt{a^(2)} = | a |. The square root of a number is always a positive number or zero. Therefore, when we take the square root of a square, we need to make sure that the result is also positive.
In the example above, we took the square root of (-3)^2, which gave us 3. We know that the square of a number is always positive, so (-3)^2 is equal to 9. However, since a can be negative or positive, we need to use the absolute value of a to make sure that we get a positive result when we take the square root.
Thus, we can conclude that sqrt{a^(2)} = | a |.