Rewriting the complex numbers in polar notation form, 1+i=2cis4π and 1−i=2cis−4π, where cisθ=cosθ+isinθ. By De Moivre's Theorem,(2cis4π)17−(2cis−4π)17=217/2(cis417π)−217/2(cis−417π)=217/2[cis(4π)−cis(−4π)]=217/2(2isin4π)=217/2⋅2⋅2−1/2i=29i=512i