雙曲餘弦

hyperbolic cosine or cosh (math.)

surname Shuang

two / double / pair / both / even (number)

hyperbola / hyperbolic (function)

surname Qu

bent / crooked / wrong

tune / song / CL:支[zhi1]

variant of 麴|曲[qu1]

yeast / Aspergillus (includes many common molds) / Taiwan pr. [qu2]

extra / surplus / remaining / remainder after division / (following numerical value) or more / in excess of (some number) / residue (math.) / after / I / me

surname Yu

variant of 餘|余[yu2], remainder

(math.) cosine

bow string / string of musical instrument / watchspring / chord (segment of curve) / hypotenuse / CL:根[gen1]