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In time 1:13 when expanding the roots. Why does the sign under the square root changes? I have tried to expand it on paper and have ended up with oposite sign. You can point out -1 and get the same result as you, lambda 1 is lambda 2 and vice versa so it gives “the same result”, but I am curious why is it changed. Does it have any specific reason or am I makin any mistake in steps of expanding?
Hey @jemelka.vaclav,
Good question - remember that i is the square root of -1. Factoring out -1 flips the signs under the larger square root sign.
S
Thank you for explanation. I get it. The sing under larger square root should have been flipped when i (square root of -1) have been factored out from there.