$\left(x-h\right)^2+\left(y-k\right)^2=r^2$  

 $y-y_1=m\left(x-x_1\right)$  

 $\tan A=\frac{\sin A}{\cos A}$  

 $FV=PV\left(1+r\right)^n$  

$y=e^x$ $\frac{dy}{dx}=e^x$

$y=e^{ax}+b$ $\frac{dy}{dx}=ae^{ax+b}$

$y=e^{f\left(x\right)}$ $\frac{dy}{dx}=f'\left(x\right)e^{f\left(x\right)}$

$\sin x$

$\cos x$

$\tan x$

$\sec^2x$

chain rule

product rule

quotient rule

30 cm rule

 $\frac{dy}{dx}=\frac{u\frac{dv}{dx}-v\frac{du}{dx}}{v^2}$  

 $\frac{dy}{dx}=\frac{v\frac{du}{dx}-u\frac{dv}{dx}}{v^2}$