Some derivatives...

Just testing out Latex on this blog.

$$\frac{d}{dx}f(g(x)) = f'(g(x))g'(x)$$
$$\frac{d}{dx}f(x)g(x) = f'(x)g(x) + f(x)g'(x)$$
$$\frac{d}{dx}\frac{f(x)}{g(x)} = \frac{f'(x)g(x) - f(x)g'(x)}{(g(x))^2}$$
$$\frac{d}{dx}b^x = b^x\ln b$$
$$\frac{d}{dx}\sec x = \sec x\tan x$$
$$\frac{d}{dx}\arctan x = \frac{1}{1 + x^2}$$

Looking good!