document.write( "Question 148500: If x = 3i is a root of the polynomial P(x) which has real coefficients, then what other root is guaranteed? \n" ); document.write( "

Algebra.Com's Answer #108823 by jim_thompson5910(35256) $\"\"$ $\"About$

You can put this solution on YOUR website!
The root $\"x+=+3i\"$ is identical to $\"x+=0%2B+3i\"$ . Since complex roots always come in conjugate pairs, this means that the other guaranteed root is $\"x+=0-3i\"$ (which is the complex conjugate to $\"x+=0%2B+3i\"$ ). So the other root is either $\"x+=0-3i\"$ or simply $\"x+=-3i\"$ \n" ); document.write( "

\n" );