实数Ａ１，Ａ２，Ａ３，Ａ４成等差数列．Ｙ＝（Ａ１加Ａ４）的平方／４Ａ１Ａ４，求Ｙ的范围
热心网友
Y≥1或Y≤0因为A1A40时(A1+A4)^2=A1^2+A4^2+2A1A4≥2A1A4+2A1A4=4A1A4(A1+A4)^2/4A1A4≥1A1A4<0时，(A1+A4)^2≥0(A1+A4)^2/4A1A4≤0
实数Ａ１，Ａ２，Ａ３，Ａ４成等差数列．Ｙ＝（Ａ１加Ａ４）的平方／４Ａ１Ａ４，求Ｙ的范围
Y≥1或Y≤0因为A1A40时(A1+A4)^2=A1^2+A4^2+2A1A4≥2A1A4+2A1A4=4A1A4(A1+A4)^2/4A1A4≥1A1A4<0时，(A1+A4)^2≥0(A1+A4)^2/4A1A4≤0