19 is a non-negative real.
This question might seem silly but this is my doubt.
we use mod. function for x2=9 i.e. x=±3
But if we just calculate the √9, we dont write ±3, though both +3 or -3 when squared equal 9.
-
UP 0 DOWN 0 0 5
5 Answers
39I suppose this is because the modulus function's domain is over the real set of numbers(both positive and negative) while the square root function accepts only non-negative reals.
66You should note that √x2 = |x|.
Basically, by definition, √x ≥ 0. Otherwise y = √x would be double valued and hence won't satisfy the requirements of the definition of a function.
11Actually √x means only positive values.
Take an example,
x2=5
or, x=(+/-)√5.
Now if √5 already meant (+/-) then we shouldnt have written (+/-)√5.