Question

A polynomial has one root that equals 2 + i. Name one other root of this polynomial.

Answer 1

do you know what a \(\bf conjugate\) is?

Answer 2

yes

Answer 3

if one root is 2+i, the other "complex" root will be the conjugate of that complex

Answer 4

so would it be 2-i?

Answer 5

yeap

Answer 6

okay thank you!

Answer 7

yw

Answer 8

recall that \(\bf \text{quadratic formula}\\
x= \cfrac{ - b \pm \sqrt { b^2 -4ac}}{2a}\) if the root gives a negative value then you have a complex number there, and you'd end up with a \(\bf \pm \) versions of it, thus conjugates of each other