- #1
nirvana1990
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Homework Statement
Show that: (cosx+isinx)^2= cos2x + isin2x
Homework Equations
i^2=-1
The Attempt at a Solution
Well, here's my attempt!
(cosx+isinx)^2=(cosx+isinx)(cosx+isinx)
=(cos^2x)+(2[isinxcosx])+(i^2sin^2x)
=(cos^2x)+(2[isinxcosx])-sin^2x
p.s. when i wrote cos^2x, for example, I meant cos squared, multiplied by x.