2-d graph

### 8.4.1 2-d graph

The plotfunc command draws the graph of a function.
funcplot is a synonym for plotfunc.

plotfunc can draw the graph of a one-variable function or a two-variable function; this section will discuss one-variable functions and the next section will discuss two-variable functions.

- plotfunc takes one mandatory argument and two optional arguments:
  - expr, an expression defining a function.
  - Optionally, var, the variable name (by default x) possibly with bounds. If the variable is given as var=a..b, the graph will be drawn from a to b, otherwise it will be graphed over the default interval (see Section 3.5.8).
  - Optionally, opt, which can be xstep=n to specify the discretization step or nstep=n to specify the number of points used to graph.
- plotfunc(expr,var ⟨opt⟩) draws the graph.

Examples.

- Input:
  plotfunc(x^2-2)
  Output:
- Input:
  plotfunc(a^2-2,a=-1..2)
  Output:
- Input:
  plotfunc(x^2-2,x,xstep=5)
  Output:
- Input:
  plotfunc(x^2-2,x=-2..3,nstep=30)
  Output: