設(shè)函數(shù)f(x)=2-x,函數(shù)g(x)的圖象與f(x)的圖象關(guān)于直線y=x對(duì)稱,函數(shù)h(x)的圖象由g(x)的圖象向左移1個(gè)單位得到,則h(x)為( )
A.-log2(x-1)
B.-log2(x+1)
C.log2(-x-1)
D.log2(-x+1)
【答案】分析:根據(jù)圖象平移的規(guī)則寫出平移之后的函數(shù)解析式是解決本題的關(guān)鍵.即根據(jù)利用關(guān)于直線y=x對(duì)稱的函數(shù)之間的關(guān)系寫出解析式g(x).再根據(jù)“左加右減,上加下減“的法則寫出h(x)的解析式.
解答:解:根據(jù)關(guān)于直線y=x對(duì)稱的函數(shù)互為反函數(shù)得出g(x)的解析式g(x)=-log2x.
函數(shù)g(x)=-log2x的圖象向左平移一個(gè)單位得到h(x)=-log2(x+1)的圖象.
故選B.
點(diǎn)評(píng):本題考查學(xué)生對(duì)圖象平移知識(shí)的理解和認(rèn)識(shí)程度,考查學(xué)生對(duì)函數(shù)圖象之間聯(lián)系的理解和把握程度,注意關(guān)于直線y=x對(duì)稱的函數(shù)互為反函數(shù)性質(zhì)的應(yīng)用.