Click here to purchase the entire book in PDF format. Dividing complex numbers The multiplicative inverse rule can be used if you're trying to divide. For example, $\frac{a}{b}$ is the same as $a * \frac{1}{b}$ therefore: $$\frac{a + jb}{c + jd} = (a + jb) * \frac{1}{c + jd}$$ (2.50) $$= \frac{(a + jb)(c - jd)}{c^{2} + d^{2}}$$ (2.51)