r^4+8r=0 怎么解出虚数根了?

r^4+8r=0 怎么解出虚数根了?
r^4+8r=0 怎么解出虚数根了?

r^4+8r=0 怎么解出虚数根了?
r(r³+8）=0
r(r+2)(r²-2r+4)=0
r=0或r+2=0或r²-2r+4=0
即r1=0,r2=-2,r3=1+√3i.r4=1-√3i