09选择题5★★★☆☆
已知 (x1,y1),(x2,y2)(x_1, y_1), (x_2, y_2) 是函数 y=2xy = 2^x 的图象上两个不同的点, 则 ()(\quad)
A.
log2y1+y22<x1+x22\log_2 \dfrac{y_1 + y_2}{2} < \dfrac{x_1 + x_2}{2}
B.
log2y1+y22>x1+x22\log_2 \dfrac{y_1 + y_2}{2} > \dfrac{x_1 + x_2}{2}
C.
log2y1+y22<x1+x2\log_2 \dfrac{y_1 + y_2}{2} < x_1 + x_2
D.
log2y1+y22>x1+x2\log_2 \dfrac{y_1 + y_2}{2} > x_1 + x_2
答案与解析

答案已隐藏