The names Ζ and ζ may refer to any of several distinct quantities or operations.

For the Riemann zeta function, see Zeta.

For the Jacobi zeta function, see JacobiZeta.

For the Weierstrass zeta function, see WeierstrassZeta.

For the Riemann zeta hypothesis, see Riemann hypothesis.

$\mathrm{\zeta }\left(2\right)$

$\frac{{\mathrm{\pi }}^2}{6}$

$\mathrm{FunctionAdvisor}\left(\mathrm{definition}\,\mathrm{JacobiZeta}\right)$

$\left[\mathrm{JacobiZeta}\left(z\,k\right)=\frac{\partial }{\partial z}\ln \left(\mathrm{JacobiTheta4}\left(\frac{\mathrm{\pi }z}{2\mathrm{EllipticK}\left(k\right)}\,\mathrm{EllipticNome}\left(k\right)\right)\right)\,\mathrm{with\; no\; restrictions\; on}\left(z\,k\right)\right]$

$\mathrm{WeierstrassZeta}\left(1.0\,2.0\,3.0\right)$

$0.944344946052752$