document.write( "Question 204916: Q.1. Find the fourth roots of -1.
\n" ); document.write( "Q.2. If 3/(2+cosx + isinx )=a+ib,then prove that a.a+b.b =4a-3. \n" ); document.write( "
Algebra.Com's Answer #154683 by stanbon(75887)\"\" \"About 
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Q.1. Find the fourth roots of -1.
\n" ); document.write( "-1 = -1+0i corresponds to the point (-1,0)
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\n" ); document.write( "r = sqrt(1^2+0^2) = 1
\n" ); document.write( "theta = tan^-1(0/-1) = 180 degrees
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\n" ); document.write( "So: -1 = 1(cos(180+360n) + isin(180+360n)
\n" ); document.write( "And (-1)^(1/4) = (1)^1/4(cos(180+360n)/4 + isin(180+360n)/4)
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\n" ); document.write( "Let n= 0 then (-1)^(1/4) = 1(cos(45) + isin(45))
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\n" ); document.write( "Let n = 1 then (-1)^(1/4) = 1(cos(135)+isin(135))
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\n" ); document.write( "Let n = 2 then (-1)^(1/4) = 1(cos(225)+ isin(225))
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\n" ); document.write( "Let n = 3 then (-1)^(1/4) = 1(cos(315)+isin(315))
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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\n" ); document.write( "\n" ); document.write( "Q.2. If 3/(2+cosx + isinx )=a+ib,then prove that a.a+b.b =4a-3.
\n" ); document.write( "Prove what?
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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