- #1
Noir
- 27
- 0
I know this isn't in the right format, but I figured I'd get a better answer here than anywhere else. In my last exam, there was a question asking to prove (a + bi - except there were values for a and b, but i forgot them) was a solution to a polynomial of the 3rd degree.
Said polynomial was complex. I sub'd it in and got 0, so it worked. Here's the catch. To find the other two solutions, I subbed -1 in for i so the equation wasn't complex. I have no idea why I did it, i just remember it working. Lo and behold I got it right, the cubic equation I got had the same solutions as the quadratic you would get if you found used the long division method. I wasn't thinking and didn't want to deal with the i's.
I want to know, does the above methord work? Subbing in -1 for i and then solving? If it does I just went from a B to an A and I'm happy. I tried looking on the internet, but couldn't find anything.
Cheers,
James.
Said polynomial was complex. I sub'd it in and got 0, so it worked. Here's the catch. To find the other two solutions, I subbed -1 in for i so the equation wasn't complex. I have no idea why I did it, i just remember it working. Lo and behold I got it right, the cubic equation I got had the same solutions as the quadratic you would get if you found used the long division method. I wasn't thinking and didn't want to deal with the i's.
I want to know, does the above methord work? Subbing in -1 for i and then solving? If it does I just went from a B to an A and I'm happy. I tried looking on the internet, but couldn't find anything.
Cheers,
James.