Only Critical Point in Town Test
If there is only one Critical Point, it must be the Extremum for functions of one variable. There areexceptions for two variables, but none of degree 
. Such exceptions include
(Wagon 1991). This latter function has discontinuous
and 
, and 
and 
.
References
Ash, A. M. and Sexton, H. ``A Surface with One Local Minimum.'' Math. Mag. 58, 147-149, 1985. Calvert, B. and Vamanamurthy, M. K. ``Local and Global Extrema for Functions of Several Variables.'' J. Austral. Math. Soc. 29, 362-368, 1980. Davies, R. Solution to Problem 1235. Math. Mag. 61, 59, 1988. Wagon, S. ``Failure of the Only-Critical-Point-in-Town Test.'' §3.4 in Mathematica in Action. New York: W. H. Freeman, pp. 87-91 and 228, 1991.
- Ditrigonal Dodecahedron
- Divergence
- Divergenceless Field
- Divergence Tests
- Divergence Theorem
- Divergent Sequence
- Divergent Series
- Diversity Condition
- Divide
- Divided Difference
- Divine Proportion
- Divisibility Tests
- Divisible
- Division
- Division Algebra
- Division Lemma
- Division Ring
- Divisor
- Divisor Function
- Divisor Theory
- Dixon-Ferrar Formula
- Dixon's Factorization Method
- Dixon's Random Squares Factorization Method
- Dixon's Theorem
- D-Number