Functions: Enter a function f(x) by writing any
expression with the `x` variable. Separate multiple
graphs with semicolons.
Trig functions: `sin(x)`, `cos(x)`, `tan(x)`, `sec(x)`,
`asin(x)` (inverse sine)
Square root: `sqrt(x)`
Natural logarithm (base e): `log(x)`
Constants: `pi`, `e`
Slope Fields: Start off with the prefix `s:` and enter
an expression in terms of `x` and `y`.
Vector Fields: Use the prefix `v:` and enter an
expression in the form of `v: (f(x, y), g(x, y))`. The 2
functions of `x` and `y` inside the paranetheses are the
x- and y-components of the vector.
Polar: Use the prefix `r = ` and enter an expression in
the form of `r = f(t)`.
Parametric: Use prefix `p:` and enter in form of
`p: x = f(t), y = g(t)`.