Question

The formula $\sqrt{ab}=\sqrt{a}\sqrt{b}$ is true if a,b are greater than 0.If true enter 1 else 0.

Answer 1

Since here both a and b are negative, we cannot apply the above formual. Thus if $a=-1$ and $b=-1,$ we cannot have $\sqrt{(-1)(-1)}=\sqrt{-1}\sqrt{-1}$ which gives the absurd result $1=-1.$