Application of test function, derivative and differential, mean value theorem and derivative. According to official website's search of Xinyang Normal University, we know that Xinyang Normal University has applied mathematics test function, derivative and differential, mean value theorem and derivative. College was founded in July, 1975, formerly known as Xinyang Branch of Kaifeng Normal University. In June, the State Council approved it as an undergraduate course, 1978, and changed its name to its current name.