Here is the mcq: $\displaystyle \sqrt{-1}*\sqrt{-1}$= a) -1 b) 1 [$\displaystyle \sqrt{-1*-1}$] c) both of a & b Thanks in advance
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Originally Posted by u2_wa Here is the mcq: $\displaystyle \sqrt{-1}*\sqrt{-1}$= a) -1 b) 1 [$\displaystyle \sqrt{-1*-1}$] c) both of a & b Thanks in advance I would say a) $\displaystyle -1 $. I was always taught that when multiplying two square roots together, the answer is what ever is under the square root sign i.e. $\displaystyle \sqrt{2}*\sqrt{2} = 2 $
Using imaginary numbers, $\displaystyle \sqrt{-1}\cdot\sqrt{-1}=i\cdot i=-1$.
TRY the darn thing on something easy; like: sqrt(4) * sqrt(4) = 2 * 2 = 4 Kapish?
Originally Posted by Wilmer TRY the darn thing on something easy; like: sqrt(4) * sqrt(4) = 2 * 2 = 4 Kapish? Everything except kapish...
And... $\displaystyle \sqrt{-1} \cdot \sqrt{-1}=(-1)^{\frac{1}{2}} \cdot (-1)^{\frac{1}{2}}=(-1)^{\frac{1}{2}+\frac{1}{2}}=(-1)^1=-1$
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