document.write( "Question 1207569: Finding the Principal Root of a Complex Number
\n" ); document.write( " (-8i)^(1/3)
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Algebra.Com's Answer #845515 by greenestamps(13200)\"\" \"About 
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\n" ); document.write( "Write the given complex number in cis(theta) form:

\n" ); document.write( "\"%288cis%28270%29%29%5E%281%2F3%29\"

\n" ); document.write( "Use deMoivre's Theorem to find the principal root:

\n" ); document.write( "\"%28%288%5E%281%2F3%29%29%28cis%28270%2F3%29%29%29=2cis%2890%29\"

\n" ); document.write( "Convert the result back to a+bi form:

\n" ); document.write( "\"2%280%2Bi%29=2i\"

\n" ); document.write( "ANSWER: 2i

\n" ); document.write( "CHECK:
\n" ); document.write( "\"%282i%29%5E3=8i%5E3=8%28-i%29=-8i\"

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