著名数学家华罗庚先生说过:“数缺形时少直观,形少数时难入微,数形结合百般好,隔裂分家万事休.”本文就是利用形象的直线“y=x”模型来研究某些递推数列问题,不仅使这一类问题的解决简捷明快,而且更具有直观性和启发性.1递推数列在某已知图象上例1(2005年辽宁高考题)一给定函数 Well-known mathematician Mr. Hua Luogeng said: “The lack of shape when the number of less intuitive, shaped when the few are hard to find, the combination of good and bad numbers, separated and separated everything off.” This article is the use of image straight line “y = x” model to study Some recursion sequence problems not only make the solution of this kind of problems simple and neat, but also more intuitive and enlightening.1 Recursion sequence given in a given image Example 1 (2005 Liaoning college entrance examination questions) given function