document.write( "Question 475313: Sir,
\n" ); document.write( "my question is how to dissolve imaginary part in an equation completely.
\n" ); document.write( "the equation is of the form cos(theeta)+jsin(theeta) & j,the imaginary part should be completely taken out by simplifying & iam not finding the solution.Pls help me
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Algebra.Com's Answer #325936 by ccs2011(207)\"\" \"About 
You can put this solution on YOUR website!
Ok so the equation is a complex number in polar form:
\n" ); document.write( "\"z+=+r%2A%28cos%28theta%29+%2B+j%2Asin%28theta%29%29\"
\n" ); document.write( "where r is the modulus or the magnitude of the distance from origin on complex plane.
\n" ); document.write( "To eliminate the imaginary part, multiply by the conjugate.
\n" ); document.write( "The conjugate is just the same number with the imaginary part having the opposite sign.
\n" ); document.write( "Ex: z = 2 + 3j, conjugate = 2 - 3j
\n" ); document.write( "In polar form the conjugate would be \"r%2A%28cos%28theta%29+-+j%2Asin%28theta%29%29\"
\n" ); document.write( "So multiply by the conjugate:
\n" ); document.write( "\"r%28cos%28theta%29+%2B+j%2Asin%28theta%29%29+%2A+r%28cos%28theta%29+-+j%2Asin%28theta%29%29\"
\n" ); document.write( "=
\n" ); document.write( "Middle term cancels
\n" ); document.write( "=\"r%5E2%28cos%5E2%28theta%29-j%5E2%2Asin%5E2%28theta%29%29\"
\n" ); document.write( "j^2 = -1
\n" ); document.write( "=\"r%5E2%28cos%5E2%28theta%29%2B+sin%5E2%28theta%29%29\"
\n" ); document.write( "trig identity, sin^2 + cos^2 = 1
\n" ); document.write( "=\"r%5E2\"
\n" ); document.write( "Hope that answered your question.
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