f(x)=1/2x^2-x+3/2 = 1/2(x-1)^2 + 1
開(kāi)口向上,對(duì)稱軸x = 1
區(qū)間【1,b】左端點(diǎn)x=1在對(duì)稱軸上,且f(1) = 1
f(b) = 1/2b^2-b+3/2 = b
b^2-2b+3 = 2b
b^2-4b+3 = 0
(b-1)(b-3) = 0
b=1,或b=3
存在大于1的實(shí)數(shù)b 使函數(shù)f(x)=1/2x平方-x+3/2在區(qū)間【1,b】上值域也是【1,b】
b=1,或b=3