Vector Algebra

$a=b\cos C+c\cos B$

$a^2=b^2+c^2-2bc\cos A$

$\cos\left(\alpha+\beta\right)$

$c^2=a^2+b^2+2bc\cos\left(\pi-A\right)$

a

b

c

B

 $\cos\alpha\cos\beta-\sin\alpha\sin\beta$  

 $\cos\alpha\cos\beta+\sin\alpha\sin\beta$  

 $\sin\alpha\cos\beta+\cos\alpha\sin\beta$  

 $\sin\alpha\cos\beta-\cos\alpha\sin\beta$  

$W=\overrightarrow{F\ }\cdot\overrightarrow{d\ }$

$W=\overrightarrow{M\ }\times\overrightarrow{F\ }$

$W=\overrightarrow{\ t\ }\times\overrightarrow{\ r\ }$

$W=\overrightarrow{F\ }\times\overrightarrow{d\ }$

$\overrightarrow{\ t\ }=\overrightarrow{\ r\ }\cdot\overrightarrow{F\ }$

$\overrightarrow{\ t\ }=\overrightarrow{\ r\ }\times\overrightarrow{F\ }$

$\overrightarrow{\ t\ }=\overrightarrow{F\ }\cdot\overrightarrow{d\ }$

$\overrightarrow{\ t\ }=\overrightarrow{F\ }\times\overrightarrow{d\ }$