Difference between revisions of "Curves"
(added examples for polar curves and link to ImplicitCurve command) |
m (→Polar curves: spacing) |
||
Line 14: | Line 14: | ||
==Polar curves== | ==Polar curves== | ||
In order to draw a curve defined using polar coordinates, it is possible to use one of the following (equivalent) syntaxes: | In order to draw a curve defined using polar coordinates, it is possible to use one of the following (equivalent) syntaxes: | ||
− | {{example| <code>ρ =sin(2 θ)</code>, or <code>sin(2 θ)</code>, or <code>f(t)=(sin(2*t); t)</code>, or <code>(sin(2*t); t)</code>, or<code>f(t)=(sin(2*t); t), 0< t < pi</code>, or <code>(sin(2*t); t), 0 < t < pi</code>, or <code>Curve[(sin(2*t); t), t, 0, 2pi]</code>. }} | + | {{example| <code>ρ=sin(2 θ)</code>, or <code>sin(2 θ)</code>, or <code>f(t)=(sin(2*t); t)</code>, or <code>(sin(2*t); t)</code>, or <code>f(t)=(sin(2*t); t), 0< t < pi</code>, or <code>(sin(2*t); t), 0 < t < pi</code>, or <code>Curve[(sin(2*t); t), t, 0, 2pi]</code>. }} |
==Implicit curves== | ==Implicit curves== |
Latest revision as of 10:29, 16 March 2017
GeoGebra supports the following types of curves:
Parametric curves
Parametric curves of the form a(t) = (f(t), g(t)) where t is real parameter within a certain range can be created:
- using the Curve Command or
- by typing their expression directly in the input bar, e.g.
(t^2,t^3)
.
Parametric curves can be used as arguments in the following commands: Tangent, Point, Intersect, Derivative, Length, Curvature, CurvatureVector and OsculatingCircle.
- Parametric curves can be used with pre-defined functions and arithmetic operations. For example, input
c(3)
returns the point at parameter position 3 on curve c. - You can also place a point on a curve using tool Point or command Point. Since the endpoints a and b are dynamic you can use slider variables as well (see tool Slider).
Creating a parametric curve through some given points is not possible. You can however try e.g. FitPoly Command to get a function going through these points.
Polar curves
In order to draw a curve defined using polar coordinates, it is possible to use one of the following (equivalent) syntaxes:
ρ=sin(2 θ)
, or sin(2 θ)
, or f(t)=(sin(2*t); t)
, or (sin(2*t); t)
, or f(t)=(sin(2*t); t), 0< t < pi
, or (sin(2*t); t), 0 < t < pi
, or Curve[(sin(2*t); t), t, 0, 2pi]
.
Implicit curves
Implicit curves are polynomials in variables x and y. The can be entered directly using the Input Bar.
The ImplicitCurve command generates an implicit curve through a list of points.
x^4 + y^3 = 2xy