Question 1032999
(x^2+1)(x^3+2x)(x^2-64)=0 
Find a root from each factor
x^2 + 1 = 0
x^2 = -1
x = {{{sqrt(-1)}}}
x = i
:
(x^3 + 2x) = 0
Factor out x
x(x^2 + 2) = 0
x = 0
and
x^2 = -2
x = {{{sqrt(-2)}}}
x = {{{sqrt(2*-1)}}}
Extract the square root of -1
x = {{{i*sqrt(2)}}}
:
x^2 - 64 = 0
Factors to
(x-8)(x+8) = 0
x = 8
and
x = -8