# Tangent planes in space: tangent

### 14.6.3 Tangent planes in space: tangent

See Section 13.7.7 for tangents in the plane.

The tangent command finds tangent planes to surfaces.

- tangent takes two arguments:
  - obj, an object in space.
  - P, a point in space.
    If obj is the graph of a function, then P can be a point in the domain of the function, and the point on the graph will be used.
  or
  - e, a point defined with element (see Section 13.6.15) using a curve and parameter value.
- tangent(objP) returns and draws the plane through P that’s perpendicular to obj.

#### Examples.

- Input:

  S: = sphere([0,0,0],3)
  tangent(S,[2,2,1])

  Output:
- Input:

  G:=plotfunc(x^2 + y^2, [x,y])
  tangent(G,[2,2])

  Output: