document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1138496>Question 1138496</A>: <I><SPAN STYLE=\"word-break: break-all;\"> third degree, only real coefficients, −2 and 2+i are two of the zeros, y-intercept is −20. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #756298 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><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/cgi-bin/show-face.mpl?user=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=756298\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> the third zero is 2-i, since complex roots are conjugate.\r<BR>\n" );
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document.write( "(x+2)(x-2-i)(x-2+i) are factors<BR>\n" );
document.write( "multiply the second and third.<BR>\n" );
document.write( "x^2-2x+ix. -2x+4-2i. -ix+2i-i^2<BR>\n" );
document.write( "This is x^2-4x+5, remembering that i^2 is -1, so that -i^2=+1<BR>\n" );
document.write( "the polynomial is x^3+2x^2-4x^2-8x+5x+10=x^3-2x^2-3x+10<BR>\n" );
document.write( "a(x^3-2x^2-3x+10) has to give a y-intercept of -20<BR>\n" );
document.write( "so a is -2<BR>\n" );
document.write( "-2x^3+4x^2+6x-20 is the polynomial.\r<BR>\n" );
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