inverse cosine vs arccosine

inverse cosine and arccosine both are nouns.

Word	Noun	Adjective	Verb	Adverb
inverse cosine	Yes	No	No	No
arccosine	Yes	No	No	No

As nouns, inverse cosine and arccosine are synonyms defined as:

inverse cosine and arccosine: the inverse function of the cosine; the angle that has a cosine equal to a given number

Other synonyms of inverse cosine include arc cosine, arccos.

inverse cosine (noun)	arccosine (noun)
the inverse function of the cosine; the angle that has a cosine equal to a given number	the inverse function of the cosine; the angle that has a cosine equal to a given number