Solution 3.1:2c
From Förberedande kurs i matematik 1
The expression \displaystyle -\text{3}^{\text{2 }} means \displaystyle -\left( \text{3} \right)^{\text{2}}\text{ }=-\text{9 } (and not \displaystyle \left( -\text{3} \right)^{\text{2}} ) and so we have
The root expression
\displaystyle \sqrt{-9}
is not defined because there is no number which, when multiplied by itself, gives
\displaystyle -\text{9}.
