80i

80i is a complex number obtained by multiplying the imaginary unit i by the real scalar 80. Since i^2 = -1, 80i has real part 0 and imaginary part 80, placing it on the positive imaginary axis of the complex plane. The magnitude (modulus) is 80 and the argument (angle) is π/2.

In rectangular form it is 0 + 80i. In polar form it can be written as 80 e^{iπ/2}, or equivalently as 80(cos π/2 + i sin π/2).

As a purely imaginary number, its conjugate is -80i. Multiplication and division with i follow i*(80i) = -80 and (80i)/i = 80. It also satisfies (80i)^2 = -6400.

Common contexts: in mathematics as a simple example of a purely imaginary number; in physics and engineering, similar expressions are used in phasor notation, where i is often replaced by j to avoid confusion with current, yielding j80.

See also: imaginary unit, complex plane, complex number.