Question

qual e a formula de a + bi de 1+2i/1-i?

Answer 1

$\frac{1+2i}{1-i} = \frac{(1+2i)(1+i)}{(1-i)(1+i)} = \frac{1+i+2i+2i^2}{1-i^2}=\frac{1+3i-2}{1-(-1)} = \\ \frac{-1+3i}{2}= -\frac{1}{2} + \frac{3}{2} i$