高中数学必考公式全总结
一、不等式
基本不等式:$\dfrac{a+b}{2} \geq \sqrt{ab}$($a,b \gt 0$,等号当 $a=b$ 时成立)
绝对值不等式:$|a| - |b| \leq |a \pm b| \leq |a| + |b|$文章源自公式库网-https://www.gongshiku.com/html/201908/eec7473764.html
二、平面向量
$\vec{a} \cdot \vec{b} = |\vec{a}||\vec{b}|\cos\theta = x_1x_2 + y_1y_2$文章源自公式库网-https://www.gongshiku.com/html/201908/eec7473764.html
$\vec{a} \perp \vec{b} \iff \vec{a}\cdot\vec{b} = 0$文章源自公式库网-https://www.gongshiku.com/html/201908/eec7473764.html
夹角公式:$\cos\theta = \dfrac{\vec{a}\cdot\vec{b}}{|\vec{a}||\vec{b}|}$文章源自公式库网-https://www.gongshiku.com/html/201908/eec7473764.html
三、立体几何
球体体积:$V = \dfrac{4}{3}\pi R^3$;表面积:$S = 4\pi R^2$文章源自公式库网-https://www.gongshiku.com/html/201908/eec7473764.html
柱体体积:$V = Sh$($S$ 底面积,$h$ 高)文章源自公式库网-https://www.gongshiku.com/html/201908/eec7473764.html
锥体体积:$V = \dfrac{1}{3}Sh$文章源自公式库网-https://www.gongshiku.com/html/201908/eec7473764.html
四、解析几何
点 $(x_0,y_0)$ 到直线 $Ax+By+C=0$ 的距离:$d = \dfrac{|Ax_0+By_0+C|}{\sqrt{A^2+B^2}}$文章源自公式库网-https://www.gongshiku.com/html/201908/eec7473764.html
圆:$(x-a)^2 + (y-b)^2 = r^2$,圆心 $(a,b)$文章源自公式库网-https://www.gongshiku.com/html/201908/eec7473764.html
椭圆:$\dfrac{x^2}{a^2} + \dfrac{y^2}{b^2} = 1$($a \gt b \gt 0$);$c^2 = a^2 - b^2$;离心率 $e = \dfrac{c}{a}$文章源自公式库网-https://www.gongshiku.com/html/201908/eec7473764.html
双曲线:$\dfrac{x^2}{a^2} - \dfrac{y^2}{b^2} = 1$;$c^2 = a^2 + b^2$;$e = \dfrac{c}{a} \gt 1$
抛物线:$y^2 = 2px$;焦点 $(\dfrac{p}{2},0)$;准线 $x = -\dfrac{p}{2}$



