Question

if x and y are non real cube roots of unity then x^7 + y^7 = ?

Answer 1

non real polynomial of unity

Answer 2

non real cube root

Answer 3

put x as \(\omega^2\)

and y as \(\omega^3\)

Answer 4

if x^3=1,y^3=1
whats x^7 ? and y^7 ??

Answer 5

@Yahoo! it will be x+y , right?

Answer 6

\[\large (w^2)^7 + (w^3)^7 = = w^{14} + w^{21}\]

Answer 7

nop....The answer should be -1/xy

Answer 8

@waterineyes how is your x w^2 ??

Answer 9

\[w^3 = 1\]

Answer 10

Soryyyyyyyyyyyyyyyyyyyyyy

Answer 11

\[(w)^7 + (w^2)^7 = w^7 + w^{14} = w^7(1 + w^7)\]

Answer 12

i got answer as -1

Answer 13

(w^7) = (w^3)^2 *w = w

Answer 14

yup, -1 is the answer and -1/xy is same as -1
because xy=1
check it out.

Answer 15

\[w^3 = 1 \implies w^7 = w^6 \cdot w = w\]

Answer 16

Yes....)

Answer 17

\[w^7 + w^{14} = w + w^2\]

Answer 18

By cube root of unity:

\[1 + w + w^2 = 0\]

So:

\[w + w^2 = -1\]

Answer 19

thxxxxx