document.write( "Question 396764: Hello, how do I figure out this complex numbers problem? Any help is greatly appreciated!\r
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document.write( "The point (-4+bi)has been plotted on the complex plane and r=8. If 0°≤θ≤180° find the value of b. Leave answer as a radical.\r
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document.write( "Thank you.
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Algebra.Com's Answer #281390 by jsmallt9(3758)![]() ![]() ![]() You can put this solution on YOUR website! The \"a\" and \"b\" in standard form and the \"r\" in polar form are related by the equation: \n" ); document.write( " \n" ); document.write( "Subsituting the value we have for \"a\" and \"r\" we get: \n" ); document.write( " \n" ); document.write( "Simplifying we get: \n" ); document.write( " \n" ); document.write( "Subtracting 16 we get: \n" ); document.write( " \n" ); document.write( "Now we find the square root of each side. Since the theta is between 0 and 180, we want \"b\" to be positive. (A negative \"b\" would put theta between 180 and 360.) So we will only use the positive square root: \n" ); document.write( " \n" ); document.write( "All that is left is simplifying: \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " |