document.write( "Question 1083651: How would you write \"sqrt%283-4i%29\" in standard form
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Algebra.Com's Answer #697675 by rothauserc(4718)\"\" \"About 
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standard form of a complex number is a + bi, where a and b are real numbers and i is the square root(-1)
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\n" ); document.write( "sqrt(3 - 4i) = a+bi
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\n" ); document.write( "square both sides of =
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\n" ); document.write( "3 - 4i = (a+bi)^2
\n" ); document.write( "3 - 4i = (a^2 + 2abi -b^2)
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\n" ); document.write( "we have two equations in two unknowns
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\n" ); document.write( "1) 3 = a^2 - b^2
\n" ); document.write( "2) -4i = 2abi
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\n" ); document.write( "solve equation 2 for a
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\n" ); document.write( "a = -4i / 2bi = -2/b
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\n" ); document.write( "substitute for a in equation 1 and solve for b
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\n" ); document.write( "b^4 +3b^2 -4 = 0
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\n" ); document.write( "let u = b^2, then
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\n" ); document.write( "u^2 +3u -4 = 0
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\n" ); document.write( "factor polynomial
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\n" ); document.write( "(u+4) * (u-1) = 0
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\n" ); document.write( "u = -4 and u = 1
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\n" ); document.write( "b^2 = -4 and b^2 = 1
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\n" ); document.write( "b = 2i, -2i, 1, -1, b is real so reject 2i and -2i
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\n" ); document.write( "a = -2/b
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\n" ); document.write( "a = -2 or 2
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\n" ); document.write( "standard form is 2 - i or -2 + i
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