modulus ♦ 1—10 of 537 matching pages ♦ SearchAdvancedHelp (0.000 seconds) 1—10 of 537 matching pages 1: 22.2 Definitions §22.2 Definitions ►The nome q is given in terms of the modulus k by … ► 22.2.3 ζ = π z 2 K ( k ) , ⓘ Symbols: π : the ratio of the circumference of a circle to its diameter, K ( k ) : Legendre’s complete elliptic integral of the first kind, z : complex, k : modulus and ζ : change of variable Permalink: http://dlmf.nist.gov/22.2.E3 Encodings: pMML, png, TeX See also: Annotations for §22.2 and Ch.22 … ► 22.2.11 p q ( z , k ) = θ p ( z | τ ) / θ q ( z | τ ) , ⓘ Symbols: θ j ( z | τ ) : theta function, p q ( z , k ) : generic Jacobian elliptic function, q : nome, z : complex, k : modulus and τ : ratio A&S Ref: 16.36.3 Referenced by: §22.2 Permalink: http://dlmf.nist.gov/22.2.E11 Encodings: pMML, png, TeX See also: Annotations for §22.2, §22.2 and Ch.22 … ► 22.2.12 τ = i K ′ ( k ) / K ( k ) , ⓘ Symbols: K ′ ( k ) : Legendre’s complementary complete elliptic integral of the first kind, K ( k ) : Legendre’s complete elliptic integral of the first kind, i : imaginary unit, k : modulus and τ : ratio Referenced by: §22.2 Permalink: http://dlmf.nist.gov/22.2.E12 Encodings: pMML, png, TeX See also: Annotations for §22.2, §22.2 and Ch.22 … 2: 22.17 Moduli Outside the Interval [0,1] §22.17 Moduli Outside the Interval [0,1] ► §22.17(i) Real or Purely Imaginary Moduli … ► 22.17.2 sn ( z , 1 / k ) = k sn ( z / k , k ) , ⓘ Symbols: sn ( z , k ) : Jacobian elliptic function, z : complex and k : modulus A&S Ref: 16.11.2 Permalink: http://dlmf.nist.gov/22.17.E2 Encodings: pMML, png, TeX See also: Annotations for §22.17(i), §22.17 and Ch.22 … ► §22.17(ii) Complex Moduli … ►For proofs of these results and further information see Walker (2003). 3: 9.8 Modulus and Phase §9.8 Modulus and Phase ► §9.8(i) Definitions … ► §9.8(ii) Identities … ► §9.8(iii) Monotonicity … ► 4: 4.30 Elementary Properties … ► Table 4.30.1: Hyperbolic functions: interrelations. … ► ► sinh θ = a cosh θ = a tanh θ = a csch θ = a sech θ = a coth θ = a ► sinh θ a ( a 2 − 1 ) 1 / 2 a ( 1 − a 2 ) − 1 / 2 a − 1 a − 1 ( 1 − a 2 ) 1 / 2 ( a 2 − 1 ) − 1 / 2 ► cosh θ ( 1 + a 2 ) 1 / 2 a ( 1 − a 2 ) − 1 / 2 a − 1 ( 1 + a 2 ) 1 / 2 a − 1 a ( a 2 − 1 ) − 1 / 2 ► tanh θ a ( 1 + a 2 ) − 1 / 2 a − 1 ( a 2 − 1 ) 1 / 2 a ( 1 + a 2 ) − 1 / 2 ( 1 − a 2 ) 1 / 2 a − 1 ► csch θ a − 1 ( a 2 − 1 ) − 1 / 2 a − 1 ( 1 − a 2 ) 1 / 2 a a ( 1 − a 2 ) − 1 / 2 ( a 2 − 1 ) 1 / 2 ► sech θ ( 1 + a 2 ) − 1 / 2 a − 1 ( 1 − a 2 ) 1 / 2 a ( 1 + a 2 ) − 1 / 2 a a − 1 ( a 2 − 1 ) 1 / 2 … ► ► 5: 10.62 Graphs … ►For the modulus functions M ( x ) and N ( x ) see §10.68(i) with ν = 0 . … ► ►► Figure 10.62.3: e − x / 2 ber x , e − x / 2 bei x , e − x / 2 M ( x ) , 0 ≤ x ≤ 8 . Magnify ► ►► Figure 10.62.4: e x / 2 ker x , e x / 2 kei x , e x / 2 N ( x ) , 0 ≤ x ≤ 8 . Magnify 6: 17.10 Transformations of ψ r r Functions … ► 17.10.1 ψ 2 2 ( a , b c , d ; q , z ) = ( a z , d / a , c / b , d q / ( a b z ) ; q ) ∞ ( z , d , q / b , c d / ( a b z ) ; q ) ∞ ψ 2 2 ( a , a b z / d a z , c ; q , d a ) , ⓘ Symbols: ψ s r ( a 1 , … , a r ; b 1 , … , b s ; q , z ) or ψ s r ( a 1 , … , a r b 1 , … , b s ; q , z ) : bilateral basic hypergeometric (or bilateral q -hypergeometric) function, ( a 1 , a 2 , … , a r ; q ) n : multiple q -Pochhammer symbol, q : complex base and z : complex variable Permalink: http://dlmf.nist.gov/17.10.E1 Encodings: pMML, png, TeX See also: Annotations for §17.10, §17.10 and Ch.17 … ► 17.10.3 ψ 8 8 ( q a 1 2 , − q a 1 2 , c , d , e , f , a q − n , q − n a 1 2 , − a 1 2 , a q / c , a q / d , a q / e , a q / f , q n + 1 , a q n + 1 ; q , a 2 q 2 n + 2 c d e f ) = ( a q , q / a , a q / ( c d ) , a q / ( e f ) ; q ) n ( q / c , q / d , a q / e , a q / f ; q ) n ψ 4 4 ( e , f , a q n + 1 / ( c d ) , q − n a q / c , a q / d , q n + 1 , e f / ( a q n ) ; q , q ) , ⓘ Symbols: ψ s r ( a 1 , … , a r ; b 1 , … , b s ; q , z ) or ψ s r ( a 1 , … , a r b 1 , … , b s ; q , z ) : bilateral basic hypergeometric (or bilateral q -hypergeometric) function, ( a 1 , a 2 , … , a r ; q ) n : multiple q -Pochhammer symbol, q : complex base and n : nonnegative integer Permalink: http://dlmf.nist.gov/17.10.E3 Encodings: pMML, png, TeX See also: Annotations for §17.10, §17.10 and Ch.17 ► 17.10.4 ψ 2 2 ( e , f a q / c , a q / d ; q , a q e f ) = ( q / c , q / d , a q / e , a q / f ; q ) ∞ ( a q , q / a , a q / ( c d ) , a q / ( e f ) ; q ) ∞ ∑ n = − ∞ ∞ ( 1 − a q 2 n ) ( c , d , e , f ; q ) n ( 1 − a ) ( a q / c , a q / d , a q / e , a q / f ; q ) n ( q a 3 c d e f ) n q n 2 . ⓘ Symbols: ψ s r ( a 1 , … , a r ; b 1 , … , b s ; q , z ) or ψ s r ( a 1 , … , a r b 1 , … , b s ; q , z ) : bilateral basic hypergeometric (or bilateral q -hypergeometric) function, ( a 1 , a 2 , … , a r ; q ) n : multiple q -Pochhammer symbol, q : complex base and n : nonnegative integer Permalink: http://dlmf.nist.gov/17.10.E4 Encodings: pMML, png, TeX See also: Annotations for §17.10, §17.10 and Ch.17 ► 17.10.5 ( a q / b , a q / c , a q / d , a q / e , q / ( a b ) , q / ( a c ) , q / ( a d ) , q / ( a e ) ; q ) ∞ ( f a , g a , f / a , g / a , q a 2 , q / a 2 ; q ) ∞ ψ 8 8 ( q a , − q a , b a , c a , d a , e a , f a , g a a , − a , a q / b , a q / c , a q / d , a q / e , a q / f , a q / g ; q , q 2 b c d e f g ) = ( q , q / ( b f ) , q / ( c f ) , q / ( d f ) , q / ( e f ) , q f / b , q f / c , q f / d , q f / e ; q ) ∞ ( f a , q / ( f a ) , a q / f , f / a , g / f , f g , q f 2 ; q ) ∞ ϕ 7 8 ( f 2 , q f , − q f , f b , f c , f d , f e , f g f , − f , f q / b , f q / c , f q / d , f q / e , f q / g ; q , q 2 b c d e f g ) + idem ( f ; g ) . ⓘ Symbols: idem ( χ 1 ; χ 2 , … , χ n ) : idem function, ϕ s r + 1 ( a 0 , … , a r ; b 1 , … , b s ; q , z ) or ϕ s r + 1 ( a 0 , … , a r b 1 , … , b s ; q , z ) : basic hypergeometric (or q -hypergeometric) function, ψ s r ( a 1 , … , a r ; b 1 , … , b s ; q , z ) or ψ s r ( a 1 , … , a r b 1 , … , b s ; q , z ) : bilateral basic hypergeometric (or bilateral q -hypergeometric) function, ( a 1 , a 2 , … , a r ; q ) n : multiple q -Pochhammer symbol and q : complex base Permalink: http://dlmf.nist.gov/17.10.E5 Encodings: pMML, png, TeX See also: Annotations for §17.10, §17.10 and Ch.17 ► 17.10.6 ( a q / b , a q / c , a q / d , a q / e , a q / f , q / ( a b ) , q / ( a c ) , q / ( a d ) , q / ( a e ) , q / ( a f ) ; q ) ∞ ( a g , a h , a k , g / a , h / a , k / a , q a 2 , q / a 2 ; q ) ∞ ψ 10 10 ( q a , − q a , b a , c a , d a , e a , f a , g a , h a , k a a , − a , a q / b , a q / c , a q / d , a q / e , a q / f , a q / g , a q / h , a q / k ; q , q 3 b c d e f g h k ) = ( q , q / ( b g ) , q / ( c g ) , q / ( d g ) , q / ( e g ) , q / ( f g ) , q g / b , q g / c , q g / d , q g / e , q g / f ; q ) ∞ ( g h , g k , h / g , k / g , a g , q / ( a g ) , g / a , a q / g , q g 2 ; q ) ∞ ϕ 9 10 ( g 2 , q g , − q g , g b , g c , g d , g e , g f , g h , g k g , − g , q g / b , q g / c , q g / d , q g / e , q g / f , q g / h , q g / k ; q , q 3 b c d e f g h k ) + idem ( g ; h , k ) . ⓘ Symbols: idem ( χ 1 ; χ 2 , … , χ n ) : idem function, ( a ; q ) n : q -Pochhammer symbol (or q -shifted factorial), ϕ s r + 1 ( a 0 , … , a r ; b 1 , … , b s ; q , z ) or ϕ s r + 1 ( a 0 , … , a r b 1 , … , b s ; q , z ) : basic hypergeometric (or q -hypergeometric) function, ψ s r ( a 1 , … , a r ; b 1 , … , b s ; q , z ) or ψ s r ( a 1 , … , a r b 1 , … , b s ; q , z ) : bilateral basic hypergeometric (or bilateral q -hypergeometric) function, ( a 1 , a 2 , … , a r ; q ) n : multiple q -Pochhammer symbol, k : nonnegative integer and q : complex base Referenced by: Erratum (V1.2.4) for Equation (17.10.6) Permalink: http://dlmf.nist.gov/17.10.E6 Encodings: pMML, png, TeX Correction (effective with 1.2.4): In the numerator of the argument of the basic bilateral hypergeometric function ψ 10 10 and in the numerator of the arguments of the basic hypergeometric ϕ 9 10 functions, we replaced q 2 by q 3 . We also added a missing factor 1 / ( k / g ; q ) ∞ in the first term on the right-hand side. See also: Annotations for §17.10, §17.10 and Ch.17 7: 17.9 Further Transformations of ϕ r r + 1 Functions … ► 17.9.2 ϕ 1 2 ( q − n , b c ; q , z ) = ( c / b ; q ) n ( c ; q ) n b n ϕ 1 3 ( q − n , b , q / z b q 1 − n / c ; q , z / c ) , ⓘ Symbols: ( a ; q ) n : q -Pochhammer symbol (or q -shifted factorial), ϕ s r + 1 ( a 0 , … , a r ; b 1 , … , b s ; q , z ) or ϕ s r + 1 ( a 0 , … , a r b 1 , … , b s ; q , z ) : basic hypergeometric (or q -hypergeometric) function, q : complex base, n : nonnegative integer and z : complex variable Referenced by: Erratum (V1.0.14) for Equation (17.9.2) Permalink: http://dlmf.nist.gov/17.9.E2 Encodings: pMML, png, TeX Correction (effective with 1.0.14): The entry q / c in the first row of ϕ 1 3 ( q − n , b , q / c b q 1 − n / c ; q , z / c ) was replaced by q / z . Suggested 2016-08-30 by Xinrong Ma See also: Annotations for §17.9(i), §17.9(i), §17.9 and Ch.17 … ► 17.9.12 ϕ 2 3 ( a , b , c d , e ; q , d e a b c ) = ( e / b , e / c , c q / a , q / d ; q ) ∞ ( e , c q / d , q / a , e / ( b c ) ; q ) ∞ ϕ 2 3 ( c , d / a , c q / e c q / a , b c q / e ; q , b q d ) − ( q / d , e q / d , b , c , d / a , d e / ( b c q ) , b c q 2 / ( d e ) ; q ) ∞ ( d / q , e , b q / d , c q / d , q / a , e / ( b c ) , b c q / e ; q ) ∞ ϕ 2 3 ( a q / d , b q / d , c q / d q 2 / d , e q / d ; q , d e a b c ) , ⓘ Symbols: ϕ s r + 1 ( a 0 , … , a r ; b 1 , … , b s ; q , z ) or ϕ s r + 1 ( a 0 , … , a r b 1 , … , b s ; q , z ) : basic hypergeometric (or q -hypergeometric) function, ( a 1 , a 2 , … , a r ; q ) n : multiple q -Pochhammer symbol and q : complex base Permalink: http://dlmf.nist.gov/17.9.E12 Encodings: pMML, png, TeX See also: Annotations for §17.9(ii), §17.9(ii), §17.9 and Ch.17 ► 17.9.13 ϕ 2 3 ( a , b , c d , e ; q , d e a b c ) = ( e / b , e / c ; q ) ∞ ( e , e / ( b c ) ; q ) ∞ ϕ 2 3 ( d / a , b , c d , b c q / e ; q , q ) + ( d / a , b , c , d e / ( b c ) ; q ) ∞ ( d , e , b c / e , d e / ( a b c ) ; q ) ∞ ϕ 2 3 ( e / b , e / c , d e / ( a b c ) d e / ( b c ) , e q / ( b c ) ; q , q ) . ⓘ Symbols: ϕ s r + 1 ( a 0 , … , a r ; b 1 , … , b s ; q , z ) or ϕ s r + 1 ( a 0 , … , a r b 1 , … , b s ; q , z ) : basic hypergeometric (or q -hypergeometric) function, ( a 1 , a 2 , … , a r ; q ) n : multiple q -Pochhammer symbol and q : complex base Referenced by: (17.9.3_5) Permalink: http://dlmf.nist.gov/17.9.E13 Encodings: pMML, png, TeX See also: Annotations for §17.9(ii), §17.9(ii), §17.9 and Ch.17 … ► 17.9.14 ϕ 3 4 ( q − n , a , b , c d , e , f ; q , q ) = ( e / a , f / a ; q ) n ( e , f ; q ) n a n ϕ 3 4 ( q − n , a , d / b , d / c d , a q 1 − n / e , a q 1 − n / f ; q , q ) = ( a , e f / ( a b ) , e f / ( a c ) ; q ) n ( e , f , e f / ( a b c ) ; q ) n ϕ 3 4 ( q − n , e / a , f / a , e f / ( a b c ) e f / ( a b ) , e f / ( a c ) , q 1 − n / a ; q , q ) . ⓘ Symbols: ϕ s r + 1 ( a 0 , … , a r ; b 1 , … , b s ; q , z ) or ϕ s r + 1 ( a 0 , … , a r b 1 , … , b s ; q , z ) : basic hypergeometric (or q -hypergeometric) function, ( a 1 , a 2 , … , a r ; q ) n : multiple q -Pochhammer symbol, q : complex base and n : nonnegative integer Permalink: http://dlmf.nist.gov/17.9.E14 Encodings: pMML, png, TeX See also: Annotations for §17.9(iii), §17.9(iii), §17.9 and Ch.17 … ► 17.9.16 ϕ 7 8 ( a , q a 1 2 , − q a 1 2 , b , c , d , e , f a 1 2 , − a 1 2 , a q / b , a q / c , a q / d , a q / e , a q / f ; q , a 2 q 2 b c d e f ) = ( a q , a q / ( d e ) , a q / ( d f ) , a q / ( e f ) ; q ) ∞ ( a q / d , a q / e , a q / f , a q / ( d e f ) ; q ) ∞ ϕ 3 4 ( a q / ( b c ) , d , e , f a q / b , a q / c , d e f / a ; q , q ) + ( a q , a q / ( b c ) , d , e , f , a 2 q 2 / ( b d e f ) , a 2 q 2 / ( c d e f ) ; q ) ∞ ( a q / b , a q / c , a q / d , a q / e , a q / f , a 2 q 2 / ( b c d e f ) , d e f / ( a q ) ; q ) ∞ ϕ 3 4 ( a q / ( d e ) , a q / ( d f ) , a q / ( e f ) , a 2 q 2 / ( b c d e f ) a 2 q 2 / ( b d e f ) , a 2 q 2 / ( c d e f ) , a q 2 / ( d e f ) ; q , q ) . ⓘ Symbols: ϕ s r + 1 ( a 0 , … , a r ; b 1 , … , b s ; q , z ) or ϕ s r + 1 ( a 0 , … , a r b 1 , … , b s ; q , z ) : basic hypergeometric (or q -hypergeometric) function, ( a 1 , a 2 , … , a r ; q ) n : multiple q -Pochhammer symbol and q : complex base Permalink: http://dlmf.nist.gov/17.9.E16 Encodings: pMML, png, TeX See also: Annotations for §17.9(iii), §17.9(iii), §17.9 and Ch.17 … 8: 10.68 Modulus and Phase Functions §10.68 Modulus and Phase Functions ► §10.68(i) Definitions … ► §10.68(ii) Basic Properties … ► §10.68(iii) Asymptotic Expansions for Large Argument … ►Additional properties of the modulus and phase functions are given in Young and Kirk (1964, pp. xi–xv). … 9: 17.8 Special Cases of ψ r r Functions … ► 17.8.4 ψ 2 2 ( b , c ; a q / b , a q / c ; q , − a q / ( b c ) ) = ( a q / ( b c ) ; q ) ∞ ( a q 2 / b 2 , a q 2 / c 2 , q 2 , a q , q / a ; q 2 ) ∞ ( a q / b , a q / c , q / b , q / c , − a q / ( b c ) ; q ) ∞ , | q a | < | b c | , ⓘ Symbols: ( a ; q ) n : q -Pochhammer symbol (or q -shifted factorial), ψ s r ( a 1 , … , a r ; b 1 , … , b s ; q , z ) or ψ s r ( a 1 , … , a r b 1 , … , b s ; q , z ) : bilateral basic hypergeometric (or bilateral q -hypergeometric) function, ( a 1 , a 2 , … , a r ; q ) n : multiple q -Pochhammer symbol and q : complex base Referenced by: Erratum (V1.2.1) for Equation (17.8.4) Permalink: http://dlmf.nist.gov/17.8.E4 Encodings: pMML, png, TeX Correction (effective with 1.2.1): The constraint | q a | < | b c | was added. See also: Annotations for §17.8, §17.8 and Ch.17 ► 17.8.5 ψ 3 3 ( b , c , d q / b , q / c , q / d ; q , q b c d ) = ( q , q / ( b c ) , q / ( b d ) , q / ( c d ) ; q ) ∞ ( q / b , q / c , q / d , q / ( b c d ) ; q ) ∞ , | q | < | b c d | , ⓘ Symbols: ψ s r ( a 1 , … , a r ; b 1 , … , b s ; q , z ) or ψ s r ( a 1 , … , a r b 1 , … , b s ; q , z ) : bilateral basic hypergeometric (or bilateral q -hypergeometric) function, ( a 1 , a 2 , … , a r ; q ) n : multiple q -Pochhammer symbol and q : complex base Referenced by: Erratum (V1.2.1) for Equation (17.8.5) Permalink: http://dlmf.nist.gov/17.8.E5 Encodings: pMML, png, TeX Correction (effective with 1.2.1): The constraint | q | < | b c d | was added. See also: Annotations for §17.8, §17.8 and Ch.17 ► 17.8.6 ψ 4 4 ( − q a 1 2 , b , c , d − a 1 2 , a q / b , a q / c , a q / d ; q , q a 3 2 b c d ) = ( a q , a q / ( b c ) , a q / ( b d ) , a q / ( c d ) , q a 1 2 / b , q a 1 2 / c , q a 1 2 / d , q , q / a ; q ) ∞ ( a q / b , a q / c , a q / d , q / b , q / c , q / d , q a 1 2 , q a − 1 2 , q a 3 2 / ( b c d ) ; q ) ∞ , | q a 3 2 | < | b c d | , ⓘ Symbols: ψ s r ( a 1 , … , a r ; b 1 , … , b s ; q , z ) or ψ s r ( a 1 , … , a r b 1 , … , b s ; q , z ) : bilateral basic hypergeometric (or bilateral q -hypergeometric) function, ( a 1 , a 2 , … , a r ; q ) n : multiple q -Pochhammer symbol and q : complex base Referenced by: Erratum (V1.2.1) for Equation (17.8.6) Permalink: http://dlmf.nist.gov/17.8.E6 Encodings: pMML, png, TeX Correction (effective with 1.2.1): The constraint | q a 3 2 | < | b c d | was added. See also: Annotations for §17.8, §17.8 and Ch.17 ► 17.8.7 ψ 6 6 ( q a 1 2 , − q a 1 2 , b , c , d , e a 1 2 , − a 1 2 , a q / b , a q / c , a q / d , a q / e ; q , q a 2 b c d e ) = ( a q , a q / ( b c ) , a q / ( b d ) , a q / ( b e ) , a q / ( c d ) , a q / ( c e ) , a q / ( d e ) , q , q / a ; q ) ∞ ( a q / b , a q / c , a q / d , a q / e , q / b , q / c , q / d , q / e , q a 2 / ( b c d e ) ; q ) ∞ , | q a 2 | < | b c d e | . ⓘ Symbols: ψ s r ( a 1 , … , a r ; b 1 , … , b s ; q , z ) or ψ s r ( a 1 , … , a r b 1 , … , b s ; q , z ) : bilateral basic hypergeometric (or bilateral q -hypergeometric) function, ( a 1 , a 2 , … , a r ; q ) n : multiple q -Pochhammer symbol and q : complex base Referenced by: Erratum (V1.2.1) for Equation (17.8.7) Permalink: http://dlmf.nist.gov/17.8.E7 Encodings: pMML, png, TeX Correction (effective with 1.2.1): The constraint | q a 2 | < | b c d e | was added. See also: Annotations for §17.8, §17.8 and Ch.17 … ► 17.8.8 ψ 2 2 ( b 2 , b 2 / c q , c q ; q 2 , c q 2 / b 2 ) = 1 2 ( q 2 , q b 2 , q / b 2 , c q / b 2 ; q 2 ) ∞ ( c q , c q 2 / b 2 , q 2 / b 2 , c / b 2 ; q 2 ) ∞ ( ( c q / b ; q ) ∞ ( b q ; q ) ∞ + ( − c q / b ; q ) ∞ ( − b q ; q ) ∞ ) , | c q 2 | < | b 2 | . ⓘ Symbols: ( a ; q ) n : q -Pochhammer symbol (or q -shifted factorial), ψ s r ( a 1 , … , a r ; b 1 , … , b s ; q , z ) or ψ s r ( a 1 , … , a r b 1 , … , b s ; q , z ) : bilateral basic hypergeometric (or bilateral q -hypergeometric) function, ( a 1 , a 2 , … , a r ; q ) n : multiple q -Pochhammer symbol and q : complex base Source: Verma and Jain (1983, (3.9)) Referenced by: §17.6(i), §17.8, Erratum (V1.1.0) for Additions, Erratum (V1.2.1) for Equation (17.8.8) Permalink: http://dlmf.nist.gov/17.8.E8 Encodings: pMML, png, TeX Addition (effective with 1.1.0): This equation was added. Suggested 2019-10-19 by Slobodan Damjanovic See also: Annotations for §17.8, §17.8 and Ch.17 … 10: 22.5 Special Values … ►For example, at z = K + i K ′ , sn ( z , k ) = 1 / k , d sn ( z , k ) / d z = 0 . (The modulus k is suppressed throughout the table.) … ►For example, sn ( 1 2 K , k ) = ( 1 + k ′ ) − 1 / 2 . … ► §22.5(ii) Limiting Values of k … ►For values of K , K ′ when k 2 = 1 2 (lemniscatic case) see §23.5(iii), and for k 2 = e i π / 3 (equianharmonic case) see §23.5(v). …