164k views
4 votes
Write the expression of polynomial a given the roots:

x = -2i and 3


Help please!!!!!!!!!!!!!!!!!!!!!?

Write the expression of polynomial a given the roots: x = -2i and 3 Help please!!!!!!!!!!!!!!!!!!!!!?-example-1

2 Answers

3 votes

Answer:

x³ - 3x² + 4x -12 = 0

Explanation:

(x-2i)(x+2i)(x-3) = 0

(x² - 4*(√-1)²)(x-3) = 0

(x² + 4) ( x - 3) = 0

x³ - 3x² + 4x -12 = 0

User IMath
by
3.7k points
3 votes

Answer:

So it looks like the given zeros are 2i and -3. We have to work backwards.

x = -3 and x = 2i

For -3, we know that out factored form before would have been x + 3

For 2i, that means we took the square root of negative number because it is imaginary. So that means out factored for x2 + 4

So if we put these together:

(x2 + 4)(x + 3) = x3 + 3x2 + 4x + 12

Upvote

1

Downvote

Add comment

Explanation:

User McArthey
by
3.3k points