Question

Find all solutions of the equation.
x^4 + 3x^3 - 12x^2 - 6x + 20 = 0

Answer 1

do you know polynomial division?

Answer 2

if not I wont be able to teach u over the net, its too hard explaining it over the net.

Answer 3

Like synthetic? yeah.

Answer 4

yeh, so you guess factors of the constant term and sub into the expression until you get a zero

Answer 5

try +-2, +-4 , +- 5

Answer 6

oh mmkay I can do that XD

Answer 7

i think it will be either 2 or 4 ,

Answer 8

should get 2

Answer 9

2 is,but I need four answers...

Answer 10

then you can say (x-2) is a factor and divide into the quartic

Answer 11

ahhh

Answer 12

but you probably dont want that, because that will reduce it to a cubic , and you will have to divide again

Answer 13

if you try other factors of 20 into the expression you will see that

(x+5) is also a factor

Answer 14

then you can divide (x-2)(x-5) into the quartic, that will leave you with a quadratic, which can be factored easily.

Answer 15

mmkay

Answer 16

is it (x-5) or (x+5)?

Answer 17

x^2-2

Answer 18

And now what?

Answer 19

?

Answer 20

yeh it should be x+5

Answer 21

then its factored, set each factor to zero find the solns

Answer 22

ohhhh so + or - sqrt2

Answer 23

yes, and then other two from the linear factors

Answer 24

:D Thanks!

Answer 25

whenever you have to solve a quadratic or higher order, first step is factor it , usually by polynomial division

Answer 26

I'll remember that.