Question

how would i write 8z^3 + 1 = 0, in the form z = re^iθ

Answer 1

z^3 = -1/8
=1/8 x e^(i(pi))
z = 1/2 x e^(i(pi)/3)

Answer 2

get it??

Answer 3

him your answer is complex. z^3=-1/8 should have solution z=(-1/2)
z=1/2*e^(i*Pi)
i think

Answer 4

wont you tak the cube root of the e^(i(pi)) part as well friend?

Answer 5

woops both are correct

Answer 6

yeah..though i can find a third root...irritating

Answer 7

i figured it out, there's 3 solns : 1/2e^i(pi) ; 1/2e^i(pi/3) ; 1/2e^i(-pi/3)

Answer 8

yes

Answer 9

yep

Answer 10

thanks guys (:

Answer 11

thnx

Answer 12

its z^3=1/8*e^(i*Pi+2Pi*n) where n is any integer. we forgot the 2*Pi*n
thenz= 1/2*e^((i*pi+2Pi*n)/3) for any integer n

Answer 13

right