> For example, what is multiplication by i+1? Without further understanding, I don't think such a question can be answered. i+1 on the plane is a vector at 45

> For example, what is multiplication by i+1? Without further understanding, I don't think such a question can be answered. i+1 on the plane is a vector at 45 degrees and a scaling of sqrt(2). So multiplying by it scales your multiplier and rotates it 45 degrees. This is a direct extension of the intuitive understanding given.