bù​biàn

invariant

不变 (不變) bù​biàn
invariant adverb
describing a mathematical property or quantity that remains unchanged under specified transformations

During the complex transformation of the formula, this constant stays the same.

constant adverb
remaining the same or unvarying in nature, quality, or condition

Even though times change, our friendship remains unchanged.

Frequency

Written text
27.7 per million

Sources

Definitions
CC-CEDICT
Frequency data
BCC Corpus (BLCU)