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Help: Proof that 1 = -1?

Yumin Wang 14, China 11 months, 3 weeks ago.

I came across something the other day involving complex numbers.

It is obvious that: $$\frac {1}{ -1} = -1 = \frac {-1}{1}$$.

If we take square roots on both sides, we get: $$\frac {1}{i} = \frac {i} {1}$$.

Multiplying gives $$1 = 1 \times 1 = i \times i = -1$$.

So, $$1 = -1$$?

I don't understand what is wrong. Can someone help?

6 comments Related to: help me!, proofs, math
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