That is true if the polynomial has real coefficientes, an this is not the case. Substitute and you will find .
Hey guys I'm not sure whether my approach to this question is right...kinda looks simple enough eh?
One root of is . Find the other root of this equation and the value of K in the form
So this is what I did:
Since is a root, is also a root as complex roots come in conjugate pairs
have I misunderstood something?...im rusty with complex numbers
The actual answers are that the other root is ,and
If a polynomial has REAL coefficients, then what you said was correct. That is, roots come in complex conjugate pairs. However, this polynomial has a complex coefficient, so what you said doesn't hold (sorry!).
Personally, I would just work out , using the fact that the coefficient of must be . It is, perhaps, crude. But it works.
Quadratic function - Wikipedia, the free encyclopedia
in this case:
a=1, b=1-i, c=-13i
It is much easier to approach the question in the way I pointed out in my post.
So, what are a and b? So what is the other root, and what is K?