imaginary vs complex quantity

imaginary and complex quantity both are nouns.

Word	Noun	Adjective	Verb	Adverb
imaginary	Yes	Yes	No	No
complex quantity	Yes	No	No	No

As nouns, imaginary and complex quantity are synonyms defined as:

imaginary and complex quantity: (mathematics) a number of the form a+bi where a and b are real numbers and i is the square root of -1

Other synonyms of imaginary include complex number, imaginary number.

imaginary (noun)	complex quantity (noun)
(mathematics) a number of the form a+bi where a and b are real numbers and i is the square root of -1	(mathematics) a number of the form a+bi where a and b are real numbers and i is the square root of -1

imaginary (adjective)	complex quantity (adjective)
not based on fact; existing only in the imagination