The complex logarithm is the complex number analogue of the logarithm function. No single valued function on the complex plane can satisfy the normal rules for logarithms. However a multivalued function can be defined which satisfies most of the identities. It is usual to consider this as a function defined on a Riemann surface. A single valued version called the principal value of the logarithm can be defined which is discontinuous on the negative x axis and equals the multivalued version on a single branch cut.

समिश्र लघुगणकीय सर्वसमिकाएँ (Complex logarithm identities)
लघुगणकीय फलनों के समाकल (Integrals)
संकलन
स्वयंस्पष्ट सर्वसमिकाएँ (Trivial identities)