document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1127716>Question 1127716</A>: <I><SPAN STYLE=\"word-break: break-all;\"> What are the zeros of the polynomial function?\r<BR>\n" );
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document.write( "Select EACH correct answer.\r<BR>\n" );
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document.write( "A. -3 \r<BR>\n" );
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document.write( "B. -1\r<BR>\n" );
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document.write( "C. 0\r<BR>\n" );
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document.write( "D. 1\r<BR>\n" );
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document.write( "E. 3\r<BR>\n" );
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document.write( "F. 7 </SPAN>\n" );
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document.write( "0 can't be a root; if it were, the constant term would be 0.<br><BR>\n" );
document.write( "Test 1 and -1 by evaluating the polynomial at those values.  It turns out f(1)=0 and f(-1)=0, so both are roots.  Roots of 1 and -1 correspond to binomial factors of x-1 and x+1; factor them out by factoring, long division, synthetic division, or any other method you know.<br><BR>\n" );
document.write( "x^4-4x^3-22x^2+4x+21 = (x-1)(x+1)(x^2-4x-21)<br><BR>\n" );
document.write( "The remaining quadratic is easily factored:<br><BR>\n" );
document.write( "x^4-4x^3-22x^2+4x+21 = (x-1)(x+1)(x-7)(x+3)<br><BR>\n" );
document.write( "The roots are 1, -1, -3, and 7.<BR>\n" );
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