"One root of is i. What are the other three roots?"
How do I do this with i?
If someone could briefly walk me through this, that'd be awesome. Thanks.
Remember, if an imaginary number is a zero to the polynomial function, so is its conjugate.
Therefore, if i is a zero, then -i is a zero.
(x-i) and (x+i) are factors.
Multiply these two together to get
Now, divide this into your original function to get
If i is a factor, and -i is a factor and is a factor then
Your zeros are