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