document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=150883>Question 150883</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0536913331/algebrahomeworkh>intermediate algebra</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> I don't know if you have that textbook, but if so you may be able to help me. in section 8.1 example 4 and 8 there are examples where the number suddenly changes into i. i ll write it down in case you don/t have the book.\r<BR>\n" );
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document.write( "the example 4:\r<BR>\n" );
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document.write( "(2x-5)2 = -16<BR>\n" );
document.write( "2x-5 = +- square root -16<BR>\n" );
document.write( "2x-5 = +- 4i<BR>\n" );
document.write( "2x=5+-4i<BR>\n" );
document.write( "x=5+-4i / 2\r<BR>\n" );
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document.write( "i have had the section about i in college but i don't understand the transition from root -16 to 4i. how does the i come into play?\r<BR>\n" );
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document.write( "8.1 example 8 is also sth with i, if you have the book it would be great if you could explain that to me as well.\r<BR>\n" );
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document.write( "anna </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #110803 by </B><A HREF=/tutors/aboutme.mpl?userid=mangopeeler07><B>mangopeeler07(462)</B></A><img src=\"/images/stars/stars-10.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=mangopeeler07><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=110803\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Dear Anna,\r<BR>\n" );
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document.write( "i is an imaginary number.  you attain the square root of any negative number by taking the square root of the opposite and multiplying it by + or - i.  So the square root of -16 is the square root of 16 (4 or -4) multiplied by i (4i or -4i). Since i^2=-1, +4i or -4i would be the sqaure root of -16, because:\r<BR>\n" );
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document.write( "4i(4i)=(4)^2(i^2)<BR>\n" );
document.write( "(4)^2(i^2)=16(-1)<BR>\n" );
document.write( "16(-1)=-16\r<BR>\n" );
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document.write( "-4i(-4i)=(-4)^2(i^2)<BR>\n" );
document.write( "(-4)^2(i^2)=16(-1)<BR>\n" );
document.write( "16(-1)=-16\r<BR>\n" );
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document.write( "I hope that this has helped you.<BR>\n" );
document.write( "Sincerely,<BR>\n" );
document.write( "Alani (mangopeeler07)<BR>\n" );
document.write( " </SPAN>\n" );
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