Question

Solve for the roots of x in each of the equations below.

x^4 - 81 = 0
x^4 + 10x^2 + 25 = 0
x^4 - x^2 - 6 = 0

Answer 1

1.) 9

Answer 2

I'm stuck on the others :/

Answer 3

notice that you can factor the first one as:
\(\large x^4-81=(x^2+9)(x^2-9) \)

so now you have the equation:
\(\large (x^2+9)(x^2-9)=0 \)

are you solving over the reals or complex ?

Answer 4

just eliminate x^2+9 because it doesnt gv real values
so x = 3,-3

Answer 5

or simply x^4 = 81
so x = +3 or -3 ^^

Answer 6

2nd is in the form of a^2+2ab+b^2
so its (x^2+5)^2
so so x^2+5 = 0
here you get complex number
x^2 = -5

Answer 7

both @ByteMe

Answer 8

@ByteMe

Answer 9

@minoz

Answer 10

81 can be written as 9*9=3*3*3*3=3^4
x^4-3^4=0=> x=+-3

Answer 11

so it wouldn't be written like (byteme) answer

Answer 12

http://www.tiger-algebra.com/drill/x~4-x~2-6=0/

Answer 13

the above link have step by step solution

Answer 14

yaa byteme answer is correct u should further solve it

Answer 15

how to further solve it? is it 3, -3?

Answer 16

3 and -3 are correct
there is also two more roots which are imaginary
x^2+9=0=>x is +-3i

Answer 17

ok thanks. Is x^2+9=0=>x is +-3i further solving it?

Answer 18

yaa so ans is +3,-3,+3i,-3i

Answer 19

x4 + 5x2 + 5x2 + 25=0
= (x2+5) • (x2+5)=0

Answer 20

The . is the multiplication sign correct?

Answer 21

just use * or (x)(y)

Answer 22

ok. what do I do next on this equation?

Answer 23

x^2+5=0=>x=+-sqrt(-5)=+-sqrt(5)i

Answer 24

I didn't see +-sqrt(-5)=+-sqrt(5)i for the answer on the website

Answer 25

My pc won't let me look at the document

Answer 26

check at 2.1 in this
soving a single variable equation
http://www.tiger-algebra.com/drill/x~4_10x~2_25=0/

Answer 27

oh I see it now

Answer 28

Can you check the last one for me? (x^2 + 2) • (x^2 - 3) = 0 x^2+2 = 0 x2 = -2 x=+-sqrt-2

Answer 29

@minoz

Answer 30

it is +-sqrt(2)i
+-sqrt(3)

Answer 31

@Power2Knowledge

Answer 32

Thank you