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Equations are pretty easy to type. If you type

The position, $x(t)$, is
$$
  x(t) = x_0 + v_0 t + \frac{1}{2} a t^2 .
$$
Eliminating $t$,
$$
    v^2(t) = \sqrt{ v_0^2 + 2 a ( x(t)  - x_0 ) }
$$

You get

The position, $x(t)$, is

$$x(t) = x_0 + v_0 t + \frac{1}{2} a t^2 .$$

Eliminating $t$,

$$v^2(t) = \sqrt{ v_0^2 + 2 a ( x(t) - x_0 ) }$$

and

The angular momentum
\[
   \vec{L} = \vec{r} \times \vec{p}
\]

produces

The angular momentum

(1)$$\vec{L} = \vec{r} \times \vec{p}$$

The full equation syntax may be a little daunting, but you probably won’t need much more than the above. For the rest, there’s Markdown.

Oh, and you can draw pictures, using the built-in drawing tool.

(Just click on the “Create SVG Graphic”) button.