No. The symbol √ signifies the principal square root of a number. Therefore, √x is always positive. The two roots of x, however, are ±√x. If you therefore have y²=x and you want to find y, you mustn’t write y=√x, but rather y=±√x to be formally correct.
Wouldn’t the square root just give plus/minus i? Seems correct enough.
No. The symbol √ signifies the principal square root of a number. Therefore, √x is always positive. The two roots of x, however, are ±√x. If you therefore have y²=x and you want to find y, you mustn’t write y=√x, but rather y=±√x to be formally correct.