Question

If a+bi is a zero of a function and the coefficients of the polynomial are real, what will be the other complex zero of the function?

1. -a + bi

2. a - bi

3. -a - bi

4. a

Answer 1

the conjugate of a binomial is simply the same binomial with a different sign in the middle, so the conjugate of x + y, is just x - y, and the conjugate of w - z is just w + z and so on.

now, complex roots never come all by their lonesome, her sister, the conjugate, is always along with her, so if the root a + bi is there, then her sister a - bi is also there too.