imaginary number

noun, Mathematics
1.
Also called imaginary, pure imaginary number. a complex number having its real part equal to zero.
Origin
1905-10
Examples from the web for imaginary number
  • Ten raised to an imaginary number can be negative, so the log of a negative number is imaginary.
  • The reference planes have been displaced in order to keep the forward transfer coefficient a purely imaginary number.
British Dictionary definitions for imaginary number

imaginary number

noun
1.
any complex number of the form ib, where i = √–1
imaginary number in Science
imaginary number
  (ĭ-māj'ə-něr'ē)   
A type of complex number in which the multiple of i (the square root of -1) is not equal to zero. Examples of imaginary numbers include 4i and 2 - 3i, but not 3 + 0i (which is just 3). See more at complex number.