一、试题及解答试题如图1,在x轴的上方,直角∠BOA绕原点O按顺时针方向旋转.若∠BOA的两边分别与函数y=-1/x、y=2/x的图像交于B、A两点,则∠OAB大小的变化趋势为().A.逐渐变小B.逐渐变大C.时大时小D.保持不变本题是2015年山东省滨州市中考数学选择题第12题,是选择题中的压轴题.本题以学生熟悉的双曲线及直角三角形为背景,主要考查反比例函数的性质、相似三角形的判定与性质、直角三角形中的边角 First, the test questions and answers questions as shown in Figure 1, above the x-axis, right angle ∠BOA clockwise rotation around the origin O. If ∠BOA both sides of the function y = -1 / x, y = 2 / x image At B, A two points, then ∠ OAB size of the change trend (). A. Gradually smaller B. Gradually become larger C. When the small small D. This question is 2015 Binzhou City, Shandong Province in the entrance exam math Multiple choice questions 12 questions, is the finale of multiple choice questions.This topic is familiar to students with hyperbolas and right triangle background, the main test of the nature of the inverse function, the determination and nature of similar triangles, right triangle corner