聚线性方程、排列组合、二项式定理于一题

从生活中一趣题谈起. 题目有10块相同的巧克力糖块,若苗苗每天至少吃1块,直到吃完,有多少种不同的吃糖方法. 分析一天吃完,一种吃法. 二天吃完,关键是余下的8块糖如何吃.实际上等价于求二元线性方程x1+x2=8的非负整数解的问题:x1+x2=8,当x1=0时,x2=8,x1=1时,x2=     

三角函数实际应用例举

三角函数在现实生产、科研中有广泛的应用.现举几例以增强应用意识及应用三角函数解决实际问题的巧妙性. [例1] 如图1所示,某村一种粮大户在承包的土地上建造一个     

Distribution Equilibrium of o-Phthalic Acid and trans-Butenedioic in Water and Di-n-butyl Phthalate

* In recentyears, the solvent-based absorption sys-tem[1], in which di-n-butyl phthalate(DBP) is usedas the solvent recovering maleic anhydride, is beingdeveloped in China. The organic solvent (di-n-butylphthalate) needs to be washed by water to recycle it-self in the process of recovering maleic anhydride[2].This is a back extraction process involved in the pro-duction of maleic anhydride. The extraction efficiencydepends on the distribution coefficients of the organicsolutes,o-phthalic aci…