二次三项式
a=4<br> 2<br> a=+4或-4<br> 根据一元二次方程判别式b^2－4ac=0求解.<br> <br><br>QUOTE:原帖由 hbxtsunge 于 2007-12-20 23:24 发表 <a href="http://bbs.pep.com.cn/redirect.php?goto=findpost&pid=3536931&ptid=346324" target="_blank"><img src="http://bbs.pep.com.cn/images/common/back.gif" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt='Click here to open new window\nCTRL+Mouse wheel to zoom in/out';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor='hand'; this.alt='Click here to open new window\nCTRL+Mouse wheel to zoom in/out';}" onclick="if(!this.resized) {return true;} else {window.open(this.src);}" onmousewheel="return imgzoom(this);" alt="" /></a><br />根据一元二次方程判别式b^2－4ac=0求解. <br>若二次三项式4x^2+ax+1是一个完全平方式，代表方程式4x^2+ax+1=0有相等实根，判别式D=a^2-16=0，所以a=4或-4<br> <br><br>QUOTE:原帖由 psmathster 于 2007-12-21 11:22 发表 <a href="http://219.239.238.42/redirect.php?goto=findpost&pid=3537491&ptid=346324" target="_blank"><img src="http://219.239.238.42/images/common/back.gif" border="0" onload="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.alt='Click here to open new window\nCTRL+Mouse wheel to zoom in/out';}" onmouseover="if(this.width>screen.width*0.7) {this.resized=true; this.width=screen.width*0.7; this.style.cursor='hand'; this.alt='Click here to open new window\nCTRL+Mouse wheel to zoom in/out';}" onclick="if(!this.resized) {return true;} else {window.open(this.src);}" onmousewheel="return imgzoom(this);" alt="" /></a><br /><br /><br />若二次三项式4x^2+ax+1是一个完全平方式，代表方程式4x^2+ax+1=0有相等实根，判别式D=a^2-16=0，所以a=4或-4 <br><img src="http://bbs.pep.com.cn/images/smilies/victory.gif" smilieid="14" border="0" alt="" /> <img src="http://bbs.pep.com.cn/images/smilies/victory.gif" smilieid="14" border="0" alt="" /><br>页:
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