Yesterday I learned about i. We use it to describe imaginary numbers. This is the definition of i: i =  -1  Now if that is true, then the following is true: i2 =i· i = -1 i3 = i2 · i = –i i4 = i3 · i = 1 i5 = i4 · i = i i6 = i4 · i2 = -1 i7 = i4 · i3 = i3 = –i i8 = i4 · i4 = 1 i9 = i8 · i = i i10 = i8 · i2 = -1 As you can see, every 4th power of i = 1. So you can just divide i‘s exponent by 4 and the remainder will tell you the answer {1,i,-1,or –i}.

These are the questions I did yesterday. A complex number has two parts – a real part and an imaginary part. For example: 3 + 6i I’ll write another post on them later.