Copmlex Number

1. Apr 9, 2009

latentcorpse

i've confused myself

$\frac{1}{i}=-i$ by multiplying by i/i

but then $(\frac{1}{i})^2=-1 \Rightarrow \frac{1}{i}= i,-i$
and clearly the positive root here doesn't make any sense???

2. Apr 9, 2009

Focus

You are correct but you forgot to take the negative root of the left hand side.

3. Apr 9, 2009

Pengwuino

Well you've somewhat answered your own question. You simply did pick the incorrect root as there are always 2 roots to a square root

$$$\begin{array}{l} 3 = 3 \\ 3^2 = 3^2 \\ 9 = 9 \\ \sqrt 9 = \sqrt 9 \\ 3 = - 3? \\ \end{array}$$$

for example.