Book:Christopher Clapham/The Concise Oxford Dictionary of Mathematics/Errata

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Errata for The Concise Oxford Dictionary of Mathematics

Fifth Edition

Accurate to $n$ Decimal Places

accurate (correct) to $n$ decimal places
$\sqrt {86.56} = 9.30076...$ is $9.30$ correct to two decimal places.


Acre

acre
In the metric system a hectare is approximately $0.4$ acre.


Normal Subgroup of Symmetric Group on More than $4$ Letters is Alternating Group

alternating group
For $n > 4$, it is the only proper, *normal subgroup of $S_n$, apart from the *empty set.


Uniform Antiprism is Semiregular Polyhedron

antiprism
If the end faces are regular and the triangular faces are equilateral, the antiprism is a semi-regular polygon.


Uniform Prism is Semiregular Polyhedron

Archimedean solid
Right-regular *prisms with square side faces ... are semi-regular [polyhedra].


Uniform Antiprism is Semiregular Polyhedron

Archimedean solid
... (right-regular) *antiprisms whose side faces are equilateral triangles are semi-regular [polyhedra].


Expansion Theorem for Determinants

cofactor
(i) The expression $a_{i1} A_{i1} + a_{i2} + \cdots + a_{in} A_{in}$ has the same value for any $i$, and is the definition of $\det \mathbf A$, the determinant of $\mathbf A$.


Cosine of Sum

compound angle formulae (in trigonometry)
$\map \cos {a \pm b} = \cos a \cos b \pm \sin a \sin b$


Equiangular Spiral

equiangular spiral
The equation can be written $r = k \theta + b$


Uniform Prism is Semiregular Polyhedron

prism
A right-regular prism in which the rectangular faces are square is semi-regular (see Archimedean solid).


Transversable Graph

transversable graph


Norbert Wiener

Wiener, Norbert (1899-1969)


Edward Witten

Witten, Edward (1957-  )


Primitive of $\dfrac 1 {\sqrt {a^2 + x^2} }$

Appendix $7$: Integrals
$\ds \int \frac {\d x} {\sqrt {a^2 + x^2} } = \dfrac 1 a \tan^{-1} {\frac x a}$


Primitive of $\sqrt {a^2 - x^2}$

Appendix $7$: Integrals
$\ds \int \sqrt {x^2 + x^2} \rd x = \frac 1 2 x \sqrt {x^2 + x^2} + \frac 1 2 a^2 \sin^{-1} \frac x a$


Sixth Edition

Accurate to $n$ Decimal Places

accurate (correct) to $n$ decimal places
$\sqrt {86.56} = 9.30076...$ is $9.30$ correct to two decimal places.


Solution Space of Nonhomogeneous Linear Equation forms Affine Space

affine space
For example, the solutions to the ODE $y' ' - y = 1$ has a solution set $S$ ...


Intersection Distributes over Union

algebra of sets
$A \cap \paren {B \cup C} = \paren {A \cap B} \cup \paren {A \cap \mathop \cap C}$


Uniform Antiprism is Semiregular Polyhedron

antiprism
If the end faces are regular and the triangular faces are equilateral, the antiprism is a semi-regular polyhedron.


Uniform Prism is Semiregular Polyhedron

Archimedean solid
Right-regular *prisms with square side faces ... are semi-regular [polyhedra].


Uniform Antiprism is Semiregular Polyhedron

Archimedean solid
... (right-regular) *antiprisms whose side faces are equilateral triangles are semi-regular [polyhedra].


Uniform Prism is Semiregular Polyhedron

prism
A right-regular prism in which the rectangular faces are square is semi-regular (see Archimedean solid).


Reduction Formula for $\ds \int \sin^n x \rd x$

Appendix $8$: Integrals: Reduction Formulae
For $I_n = \int \sin^n x \rd x$, where $n \ge 2$, then
$I_n = -\dfrac {\sin^n x \cos x} n + \dfrac {n - 1} n I_{n - 2}$.


Reduction Formula for $\ds \int \sin^n x \rd x$

Appendix $8$: Integrals: Reduction Formulae
For $I_n = \int \cos^n x \rd x$, where $n \ge 2$, then
$I_n = \dfrac {\cos^n x \sin x} n + \dfrac {n - 1} n I_{n - 2}$.