document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=459274>Question 459274</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find to the nearest tenth of a degree ,all values of x in the interval 0 less than/equal to x lessthan/equal to 360 degrees that satisfy the equation 4cos^2x-5sinx-5=0\r<BR>\n" );
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document.write( "Can you please help me answer this? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #314972 by </B><A HREF=/tutors/aboutme.mpl?userid=Gogonati><B>Gogonati(855)</B></A><img src=\"/images/stars/stars-11.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Gogonati><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=Gogonati><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=314972\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> First we simplify this equation:<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=4%281-%28sinx%29%5E2%29-5sinx-5=0 ALIGN=MIDDLE  ALT=\"4%281-%28sinx%29%5E2%29-5sinx-5=0\"   DISABLED_style= \"max-width:90%; height:auto;\" >=>\r<BR>\n" );
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document.write( "=><IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=4-4%28sinx%29%5E2-5sinx-5=0 ALIGN=MIDDLE  ALT=\"4-4%28sinx%29%5E2-5sinx-5=0\"   DISABLED_style= \"max-width:90%; height:auto;\" >=><IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=4%28sinx%29%5E2%2B5sinx%2B1=0 ALIGN=MIDDLE  ALT=\"4%28sinx%29%5E2%2B5sinx%2B1=0\"   DISABLED_style= \"max-width:90%; height:auto;\" >. \r<BR>\n" );
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document.write( "In the last equation we substitute <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sinx=y ALIGN=MIDDLE  ALT=\"sinx=y\"   DISABLED_style= \"max-width:90%; height:auto;\" >, and get the quadratic equation:\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=4y%5E2%2B5y%2B1=0 ALIGN=MIDDLE  ALT=\"4y%5E2%2B5y%2B1=0\"   DISABLED_style= \"max-width:90%; height:auto;\" >, solving this equation we get: y=-1 and y=-1/4.\r<BR>\n" );
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document.write( "Remembering our substitution <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=+sinx ALIGN=MIDDLE  ALT=\"y=+sinx\"   DISABLED_style= \"max-width:90%; height:auto;\" > we need to solve two simple \r<BR>\n" );
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document.write( "trigonometric equations equivalent with our original equation.\r<BR>\n" );
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document.write( "1)<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sinx=-1 ALIGN=MIDDLE  ALT=\"sinx=-1\"   DISABLED_style= \"max-width:90%; height:auto;\" >, where <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=3%2Api%2F2 ALIGN=MIDDLE  ALT=\"x=3%2Api%2F2\"   DISABLED_style= \"max-width:90%; height:auto;\" >, and\r<BR>\n" );
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document.write( "2)<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=sinx=-1%2F4 ALIGN=MIDDLE  ALT=\"sinx=-1%2F4\"   DISABLED_style= \"max-width:90%; height:auto;\" >, where <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=-0.25 ALIGN=MIDDLE  ALT=\"x=-0.25\"   DISABLED_style= \"max-width:90%; height:auto;\" >, and <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=2%2Api%2B0.25 ALIGN=MIDDLE  ALT=\"x=2%2Api%2B0.25\"   DISABLED_style= \"max-width:90%; height:auto;\" >. </SPAN>\n" );
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