Eli5: in complex numbers, what is the meaning of adding a “+b*i” part? It looks to me similar to ‘normal’ coordinates (+b*y), but with another name. I understand that the meaning of i as the square root of a negative makes it different but could never understand how so.

Question

We were told about complex numbers, and did the algebra by solving problems with the general form of “a*n + b*i”. It does not really behave differently than standard algebra, it seems. What am I missing in the intention or meaning of the “i” part?

In: Mathematics

Answer 1

Every number has a real part and an imaginary part. Like 5 would be 5 + 0i. It’s there because imaginary numbers are used as a way to make the negatives have square roots and stuff (I think I might’ve forgotten) and they usually loop back to a real counterpart.

Check out [this](https://youtu.be/Z49hXoN4KWg) video for more!