2018/9/7,2018/9/7,第 三 节,导数的实际应用,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,用料费用最省问题,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,利润最大问题,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,答案：85,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,面积、体积(容积)最大问题,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,用时最短问题,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,A40 B60 C80 D120 答案 C,2018/9/7,2018/9/7,2018/9/7,答案 C,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,2018/9/7,时音1对1，是中国高端在线教育辅导机构，2014年成立，已经成为全国范围内受众多家长和学生信赖的在线精品教学产品，时音聚集的老师都来自清华大学、北京大学、上海交通大学、复旦大学、浙江大学等TOP10名校，聘请一线老师组成的全职教研团队，钻研中高考命题规律，为了能让学生“足不出户选老师，高效便捷提分快”，时音致力成为线上精品教学的领导者。 服务对象包括：高中生，初中生 学科辅导：数学、英语、物理、化学、生物、地理、语文、历史、政治,2018/9/7,