write the polynomial equation whose roots (zeros) are: 2, -1, 5

Question

parthkohli · Answer

Would look something like $f(x) = (x - 2)(x + 1)(x - 5)$

parthkohli · Answer

jackellyn · Answer

I answered this in your previous question.

(x-2)(x+1)(x-5)
Expand by foil-ing/distributing

anonymous · Answer

sorry, they kept telling me to make a new question!

anonymous · Answer

(x-2)(x+1)(x-5)

jackellyn · Answer

@clcboo123
(x-2)(x+1)(x-5) 
(x^2 +x-2x-2)(x-5) 
x^3 -5x^2 -x^2 +5x -2x +10 
x^3 -6x^2 +3x +10

anonymous · Answer

ohh okay, so for instants -1,4, 2, -3 would be x+1 x-4 x-2 x+3?

anonymous · Answer

and then foil it

jackellyn · Answer

That would be the roots and to find out the equation you would have to distribute or foil each yeah.

anonymous · Answer

okay. what if its with imginary numbes 2i, -2i, 3

jackellyn · Answer

(x-2i)(x+2i)(x-3)

Same thing.

anonymous · Answer

when you combine 2i and a x what is that?

jackellyn · Answer

In this example, the 2x(i) or 2i(x) cancels

x^2 +2i(x)-2i(x)-4i^2
x^2 - 4i^2
x^2 - 4 (-1)
(x^2 + 4)