Question

16£®ÏÂÃæÊÇijͬѧ¶Ô¶àÏîʽ£¨x²-4x+2£©£¨x²-4x+6£©+4½øÐÐÒòʽ·Ö½âµÄ¹ý³Ì£®
½â£ºÉèx²-4x=y
ԭʽ=£¨y+2£©£¨y+6£©+4£¨µÚÒ»²½£©
=y²+8y+16£¨µÚ¶þ²½£©
=£¨y+4£©²£¨µÚÈý²½£©
=£¨x²-4x+4£©²£¨µÚËIJ½£©
ÇëÎÊ£º
£¨1£©¸ÃͬѧµÚ¶þ²½µ½µÚÈý²½ÔËÓÃÁËÒòʽ·Ö½âµÄC
A£®ÌáÈ¡¹«Òòʽ·¨    B£®Æ½·½²î¹«Ê½
C£®Á½ÊýºÍµÄÍêȫƽ·½¹«Ê½    D£®Á½Êý²îµÄÍêȫƽ·½¹«Ê½
£¨2£©¸ÃͬѧÒòʽ·Ö½âµÄ½á¹ûÊÇ·ñ³¹µ×£¿²»³¹µ×£®£¨Ìî¡°³¹µ×¡±»ò¡°²»³¹µ×¡±£©
Èô²»³¹µ×£¬ÇëÖ±½Óд³öÒòʽ·Ö½âµÄ×îºó½á¹û£¨x-2£©⁴
£¨2£©ÇëÄãÄ£·ÂÒÔÉÏ·½·¨³¢ÊÔ¶Ô¶àÏîʽ£¨x²-2x£©£¨x²-2x+2£©+1½øÐÐÒòʽ·Ö½â£®

Answer 1

·ÖÎö £¨1£©¹Û²ì·Ö½â¹ý³Ì·¢ÏÖÀûÓÃÁËÍêȫƽ·½¹«Ê½£»
£¨2£©¸Ãͬѧ·Ö½â²»³¹µ×£¬×îºóÒ»²½»¹ÄÜÀûÓÃÍêȫƽ·½¹«Ê½·Ö½â£»
£¨3£©·ÂÕÕÌâÖз½·¨½«Ô­Ê½·Ö½â¼´¿É£®

½â´ð ½â£º£¨1£©¸ÃͬѧµÚ¶þ²½µ½µÚÈý²½ÔËÓÃÁËÒòʽ·Ö½âµÄÁ½ÊýºÍµÄÍêȫƽ·½¹«Ê½£¬Ñ¡ÔñC£¬
¹Ê´ð°¸Îª£ºC£»
£¨2£©¸ÃͬѧÒòʽ·Ö½âµÄ½á¹û²»³¹µ×£¬×îºó½á¹ûΪ£¨x-2£©⁴£»
¹Ê´ð°¸Îª£º²»³¹µ×£»£¨x-2£©⁴£»
£¨3£©Ô­Ê½=£¨x²-2x£©²+2£¨x²-2x£©+1=£¨x²-2x+1£©²=£¨x-1£©⁴£®

µãÆÀ ´ËÌ⿼²éÁËÒòʽ·Ö½â-ÔËÓù«Ê½·¨£¬ÊìÁ·ÕÆÎÕÒòʽ·Ö½âµÄ·½·¨ÊǽⱾÌâµÄ¹Ø¼ü£®