Click here to purchase the entire book in PDF format. Additive Inverse Every number has what is known as an additive inverse - a matching number which when added to its partner equals 0. For example, the additive inverse of 2 is -2 because 2 + -2 = 0. This additive inverse can be found by mulitplying the number by -1 so, in the case of complex numbers: $$(a + jb) + (-a + -jb) = 0$$ (2.41) Therefore, the additive inverse of (a + jb) is (-a - jb)