The matrix representation of this number is an antidiagonal 2-by-2 matrix with entries negative one and positive one.
The matrix representation of this number is an antidiagonal 2-by-2 matrix with entries negative one and positive one. The argument of this number is pi over 2. This is the only number on the upper unit half-circle which is equal to the negative of its conjugate. This number multiplies the sine function in de Moivre's formula. This constant appears in the exponent in Euler's formula. The cube of this nonzero number equals negative one times itself. e to the power of "pi times this" equals negative one. Adding a nonzero multiple of this unit number to a real number yields a strictly complex number. For 10 points, name the imaginary unit, defined as the square root of negative one.
The matrix representation of this number is an antidiagonal 2-by-2 matrix with entries negative one and positive one.
i [or j; or negative i; or negative j; accept the imaginary unit until mentioned; accept the unit imaginary number until "imaginary unit"; accept the square root of negative one until mentioned; accept mathematically-equivalent answers] 