Question

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£©
£¨1£©¸ÃͬѧµÚ¶þ²½µ½µÚÈý²½ÔËÓÃÁËÒòʽ·Ö½âµÄ______£®
A£®ÌáÈ¡¹«Òòʽ
B£®Æ½·½²î¹«Ê½
C£®Á½ÊýºÍµÄÍêȫƽ·½¹«Ê½
D£®Á½Êý²îµÄÍêȫƽ·½¹«Ê½
£¨2£©¸ÃͬѧÒòʽ·Ö½âµÄ½á¹ûÊÇ·ñ³¹µ×£¿______£®£¨Ìî¡°³¹µ×¡±»ò¡°²»³¹µ×¡±£©Èô²»³¹µ×£¬ÇëÖ±½Óд³öÒòʽ·Ö½âµÄ×îºó½á¹û______£®
£¨3£©ÇëÄãÄ£·ÂÒÔÉÏ·½·¨³¢ÊÔ¶Ô¶àÏîʽ£¨x²-2x£©£¨x²-2x+2£©+1½øÐÐÒòʽ·Ö½â£®

Answer 1

£¨1£©¸ÃͬѧµÚ¶þ²½µ½µÚÈý²½ÔËÓÃÁËÒòʽ·Ö½âµÄÊýºÍµÄÍêȫƽ·½¹«Ê½£»
¹ÊÑ¡£ºC£»

£¨2£©¸ÃͬѧÒòʽ·Ö½âµÄ½á¹û²»³¹µ×£¬
ԭʽ=£¨x²-4x+4£©²=£¨x-2£©⁴£»
¹Ê´ð°¸Îª£º²»³¹µ×£¬£¨x-2£©⁴£»

£¨3£©£¨x²-2x£©£¨x²-2x+2£©+1
=£¨x²-2x£©²+2£¨x²-2x£©+1
=£¨x²-2x+1£©²
=£¨x-1£©⁴£®