Answer: Choice A
Step-by-step explanation:
The square root undoes the squaring operation.
Think of a square that is 1 ft by 1 ft. Its area would be 1*1 = 1 sq ft.
Now imagine you told your friend "the area is 1 sq ft" and you didn't relay the side lengths. Your friend would use the square root to find the side length is 1 ft.
I'm not sure why your teacher is using plus minus notation when that is not correct. Saying
is not true. The result of a square root is simply one value only. If your teacher meant
, then it would be a true statement; however, there's no need to involve negative numbers for this problem.