单选题由函数y=-x2的图象平移得到函数y=-（x-4）2+5的图象，则这个平移是A.

单dān选xuǎn题由yóu函hán数shùy=-1/2x2的de图象xiàng平píng移yí得dé到dào函hán数shùy=-1/2（x-4）2+5的de图象xiàng，则这zhè个gè平píng移yí是shì

A.先xiān向xiàng左zuǒ平píng移yí4个gè单dān位wèi，再zài向xiàng下平píng移yí5个gè单dān位wèiB.先xiān向xiàng左zuǒ平píng移yí4个gè单dān位wèi，再zài向xiàng上shàng平píng移yí5个gè单dān位wèiC.先xiān向xiàng右yòu平píng移yí4个gè单dān位wèi，再zài向xiàng下平píng移yí5个gè单dān位wèiD.先xiān向xiàng右yòu平píng移yí4个gè单dān位wèi，再zài向xiàng上shàng平píng移yí5个gè单dān位wèi,D解jiě析xī分fēn析xī：求得dé原yuán抛pāo物wù线xiàn的de顶dǐng点diǎn坐zuò标biāo及jí新抛pāo物wù线xiàn的de顶dǐng点diǎn坐zuò标biāo，看kàn顶dǐng点diǎn坐zuò标biāo是shì如何hé平píng移yí得dé到dào的de即可kě．

解jiě答：∵函hán数shùy=-x2的de顶dǐng点diǎn为wèi（0，0）；函hán数shùy=-（x-4）2+5的de顶dǐng点diǎn为wèi（4，5），（0，0）向xiàng右yòu平píng移yí4个gè单dān位wèi，再zài向xiàng上shàng平píng移yí5个gè单dān位wèi可kě得dé到dào（4，5），∴函hán数shù图象xiàng的de平píng移yí也是shì先xiān向xiàng右yòu平píng移yí4个gè单dān位wèi，再zài向xiàng上shàng平píng移yí5个gè单dān位wèi得dé到dào的de，故gù选xuǎnD．点diǎn评píng：用yòng到dào的de知识shí点diǎn为wèi：抛pāo物wù线xiàn图象xiàng的de平píng移yí和hé抛pāo物wù线xiàn顶dǐng点diǎn的de平píng移yí一yī致zhì．