13.18.2 Envelopes: envelope
The envelope command draws the envelope of a family of curves.
-
envelope takes two arguments:
-
expr, an expression of two variables and one
parameter.
- L, a list of the names of the variables and the
parameters. If the variables are x and y,
then L only need to be the name of the parameter.
- envelope(expr,L)
draws the envelope of the family of curves given by
expr=0 over the parameter.
Examples.
-
Input:
envelope(y + x*tan(t) - 2*sin(t),t)
Output:
- Input:
envelope(v + u*tan(s) - 2*sin(s),[u,v,s])
Output:
