### 12.6.3 Tangent planes in space: tangent

See section 11.7.7 for tangents in the plane.

The tangent command takes as argument a geometric object and
a point on the object.

tangent draws and returns the plane through the point tangent
to the object.

Input:

S: = sphere([0,0,0],3)

then:

tangent(S,[2,2,1])

Output:

If the geometric object is the graph of a function, then the second
argument is a point in the domain of the function; the corresponding point
on the graph will be used.

Input:

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

then:

tangent(G,[2,2])

Output: