Question

can someone show me the steps on how to solve to find the zeros of x4-15x2-16, or x3+4x2-3x-12, or x4+2x3+2x2+2x+1

Answer 1

(Welcome to OpenStudy)

Answer 2

can you help?

Answer 3

Nah I'm too stupid. Sorry dude.

Answer 4

But I have a few people who can!

Answer 5

@karatechopper

Answer 6

I SUMMON THEE!!!

Answer 7

@uri @Ashleyisakitty @poopsiedoodle @AccessDenied @saifoo.khan @Preetha @Callisto

I SUMMON THEE WITH THE POWER OF TAG!!!

Answer 8

HELP THIS LOST ONE!!!

Answer 9

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Answer 10

Wth this is supposed to work!

Answer 11

okay? i just really neeed help

Answer 12

Aha! It worked! Please help!

Answer 13

Next time..Pm them..

Answer 14

for welcoming..

Answer 15

@zsoccer needs help, O mighty one..............

Answer 16

agreed like now please :)

Answer 17

We tremble in your presence! Aid the first-timer, O magnificent one! All seeing! Wielder of the Ban Hammer!

Answer 18

your weird.

Answer 19

WTF where'd he go? Aw well you can't always trust mods.

Answer 20

Oh well. Now you got no help!

Answer 21

Sorry! I tried to summon, but I guess they're busy.

Answer 22

@zsoccer

Zeroes of x^4-15x^2-16 are values of x which render the given expression to have a value of zero.

First step:

Factor: x^4 - 15x^2 - 16

Answer 23

\[x^4-15x^2-16\]\[u=x^2\]\[(x^2)^2-15(x^2)-16\]\[u^2-15u-16\]\[(u-16)(u+1)\]\[(x^2-16)(x^2+1)\]\[(x+4)(x-4)(x^2+1)\]Set equal to zero\[(x+4)(x-4)(x^2+1)=0\]\[x=-4,\ 4,\ i,\ -i\]

Answer 24

verification of above problem's solution: http://www.wolframalpha.com/input/?i=x^4-15x^2-16%3D0

Answer 25

\[x^3+4x^2-3x-12\]\[x^2(x+4)-3(x+4)\]\[(x^2-3)(x+4)\]\[(x+\sqrt{3})(x-\sqrt{3})(x+4)\]
Set equal to zero, obtain

x = +/- sqrt(3), x = - 4

verification: http://www.wolframalpha.com/input/?i=x^3%2B4x^2-3x-12%3D0

Answer 26

\[x^4+2x^3+2x^2+2x+1\]\[x^4+2x^3+x^2+x^2+2x+1\]\[x^2(x^2+2x+1)+1(x^2+2x+1)\]\[(x^2+1)(x^2+2x+1)\]\[(x^2+1)(x+1)(x+1)\]\[(x^2+1)(x+1)^2\]Set equal to zero\[(x^2+1)(x+1)^2=0\]\[x=-1,\ +/-i\]

verification of solutions: http://www.wolframalpha.com/input/?i=x^4%2B2x^3%2B2x^2%2B2x%2B1%3D0