20.3 Graphics20.5 Infinite Products and Related Results

§20.4 Values at z = 0

Contents

§20.4(i) Functions and First Derivatives

20.4.1\mathop{\theta _{{1}}\/}\nolimits\!\left(0,q\right)={\mathop{\theta _{{2}}\/}\nolimits^{{\prime}}}\!\left(0,q\right)={\mathop{\theta _{{3}}\/}\nolimits^{{\prime}}}\!\left(0,q\right)={\mathop{\theta _{{4}}\/}\nolimits^{{\prime}}}\!\left(0,q\right)=0,
20.4.2{\mathop{\theta _{{1}}\/}\nolimits^{{\prime}}}\!\left(0,q\right)=2q^{{1/4}}\prod\limits _{{n=1}}^{{\infty}}\left(1-q^{{2n}}\right)^{3},
20.4.3\mathop{\theta _{{2}}\/}\nolimits\!\left(0,q\right)=2q^{{1/4}}\prod\limits _{{n=1}}^{{\infty}}\left(1-q^{{2n}}\right)\left(1+q^{{2n}}\right)^{2},
20.4.4\mathop{\theta _{{3}}\/}\nolimits\!\left(0,q\right)=\prod\limits _{{n=1}}^{{\infty}}\left(1-q^{{2n}}\right)\left(1+q^{{2n-1}}\right)^{2},
20.4.5\mathop{\theta _{{4}}\/}\nolimits\!\left(0,q\right)=\prod\limits _{{n=1}}^{{\infty}}\left(1-q^{{2n}}\right)\left(1-q^{{2n-1}}\right)^{2}.

Jacobi’s Identity

20.4.6{\mathop{\theta _{{1}}\/}\nolimits^{{\prime}}}\!\left(0,q\right)=\mathop{\theta _{{2}}\/}\nolimits\!\left(0,q\right)\mathop{\theta _{{3}}\/}\nolimits\!\left(0,q\right)\mathop{\theta _{{4}}\/}\nolimits\!\left(0,q\right).

§20.4(ii) Higher Derivatives

20.4.7{\mathop{\theta _{{1}}\/}\nolimits^{{\prime\prime}}}(0,q)={\mathop{\theta _{{2}}\/}\nolimits^{{\prime\prime\prime}}}\!\left(0,q\right)={\mathop{\theta _{{3}}\/}\nolimits^{{\prime\prime\prime}}}\!\left(0,q\right)={\mathop{\theta _{{4}}\/}\nolimits^{{\prime\prime\prime}}}\!\left(0,q\right)=0.
20.4.8\frac{{\mathop{\theta _{{1}}\/}\nolimits^{{\prime\prime\prime}}}\!\left(0,q\right)}{{\mathop{\theta _{{1}}\/}\nolimits^{{\prime}}}\!\left(0,q\right)}=-1+24\sum _{{n=1}}^{{\infty}}\frac{q^{{2n}}}{(1-q^{{2n}})^{2}}.
20.4.9\frac{{\mathop{\theta _{{2}}\/}\nolimits^{{\prime\prime}}}\!\left(0,q\right)}{\mathop{\theta _{{2}}\/}\nolimits\!\left(0,q\right)}=-1-8\sum _{{n=1}}^{{\infty}}\frac{q^{{2n}}}{(1+q^{{2n}})^{2}},
20.4.10\frac{{\mathop{\theta _{{3}}\/}\nolimits^{{\prime\prime}}}\!\left(0,q\right)}{\mathop{\theta _{{3}}\/}\nolimits\!\left(0,q\right)}=-8\sum _{{n=1}}^{{\infty}}\frac{q^{{2n-1}}}{(1+q^{{2n-1}})^{2}},
20.4.11\frac{{\mathop{\theta _{{4}}\/}\nolimits^{{\prime\prime}}}\!\left(0,q\right)}{\mathop{\theta _{{4}}\/}\nolimits\!\left(0,q\right)}=8\sum _{{n=1}}^{{\infty}}\frac{q^{{2n-1}}}{(1-q^{{2n-1}})^{2}}.
20.4.12\frac{{\mathop{\theta _{{1}}\/}\nolimits^{{\prime\prime\prime}}}\!\left(0,q\right)}{{\mathop{\theta _{{1}}\/}\nolimits^{{\prime}}}\!\left(0,q\right)}=\frac{{\mathop{\theta _{{2}}\/}\nolimits^{{\prime\prime}}}\!\left(0,q\right)}{\mathop{\theta _{{2}}\/}\nolimits\!\left(0,q\right)}+\frac{{\mathop{\theta _{{3}}\/}\nolimits^{{\prime\prime}}}\!\left(0,q\right)}{\mathop{\theta _{{3}}\/}\nolimits\!\left(0,q\right)}+\frac{{\mathop{\theta _{{4}}\/}\nolimits^{{\prime\prime}}}\!\left(0,q\right)}{\mathop{\theta _{{4}}\/}\nolimits\!\left(0,q\right)}.