考研数学二必背公式及知识点(自己精心总结整理)(可复制)
高数概念[基础知识]因式分解公式:a^{n}-b^{n}=(a-b)(a^{n-1}+a^{n-2}b+\cdots+ab^{n-2}+b^{n-1})(n为正偶数时()a^{n}-b^{n}=(a+b)(a^{n-1}-a^{n-2}b+\cdots+ab^{n-2}-b^{n-1})(n为正奇数时(a^{n}+b^{n}=(a+b)(a^{n-1}-a^{n-2}b+\cdots -ab^{n-2}+b^{n-1})二项式定理:(a+b)^{n}= \sum _{k=0}^{n}C_{n}^{k}a^{k}b^{n-k}不等式:(1)a,b位实数,则\varnothing 2|ab| \le a^{2}+b^{2};\circled {2}|a \pm b| \le |a|+|b|; \circled {3}|a|-|b| \le |a-b|.(2)a_{1},a_{2}, \cdots ,a_{n}>0,则\frac {a_{1}+a_{2}+\cdots+a_{n}}{n} \ge \sqrt [n]{a_{1}a_{2} \cdots a_{n}}取整函数:\mid x-1<[x] \le x三角函数和差化积;积化和差(7):\sin \alpha+\sin \beta =2(\sin \frac { \alpha+\beta }{2})(\cos \frac { \alpha - \beta }{2})\sin \alpha \cos \beta = \frac {1}{2}(\sin \frac { \alpha+\beta }{2}+\cos \frac { \alpha - \beta }{2})\sin \alpha - \sin \beta =2(\cos \frac { \alpha+\beta }{2})(\sin \frac { \alpha - \beta }{2})\cos \alpha \cos \beta = \frac {1}{2}(\cos \frac { \alpha+\beta }{2}+\cos \frac { \alpha - \beta }{2})\cos \alpha+\cos \beta =2(\cos \frac { \alpha+\beta }{2})(\cos \frac { \alpha - \beta }{2})\sin \alpha \sin \beta =- \frac {1}{2}(\cos \frac { \alpha+\beta }{2}- \cos \frac { \al