ACTUALLY
1) If the square root is written into the question then, by convention, the answer is POSITIVE.
$$\sqrt{4}=+2$$
2) However, if the question is
$$x^2=4$$
then this is how you solve it
$$\sqrt{x^2}=\pm\sqrt{4}\\
x=\:\pm\; 2$$
This is because the square root was not a part of the question. It was introduced as a part of the solution.
So this time there are 2 answers, +2 and -2
ACTUALLY
1) If the square root is written into the question then, by convention, the answer is POSITIVE.
$$\sqrt{4}=+2$$
2) However, if the question is
$$x^2=4$$
then this is how you solve it
$$\sqrt{x^2}=\pm\sqrt{4}\\
x=\:\pm\; 2$$
This is because the square root was not a part of the question. It was introduced as a part of the solution.
So this time there are 2 answers, +2 and -2