Question 399498
Is it
{{{sqrt((a+2)^2)}}}
or
{{{(sqrt(a+2))^2}}}?
It makes a difference. In the first expression we do not know if (a+2) is positive or negative. In the second expression, since a+2 is inside of a square root, we know that a+2 cannot be negative.<br>
Both of these expressions look like they would simplify to a+2. But square roots are supposed to be positive (or zero). With the first expression, since we do not if a+2 is positive we must use absolute value to ensure that we have a positive (or zero) result.
{{{sqrt((a+2)^2) = abs(a+2)}}}<br>
With the second expression, since we know that a+2 cannot be negative, we do not need absolute value:
{{{(sqrt(a+2))^2 = a+2}}}