How many complex roots does 6x^4 + x^3-5 = 0 have?

Question

welshfella · Answer

you can use descarte's rule of signs to find this. I cant remember the detail I'm afraid...

anonymous · Answer

I know it has something to do with the greatest power, and the constant.

welshfella · Answer

one root is -1 so there's possibly 2 complex roots

anonymous · Answer

find p/q  , use synthetic to compress the polynomial until power 2, then use quadratic to solve. Hope it helps

anonymous · Answer

I thought the same thing too, it only gives my the choices 3, 4, 5, and 6

welshfella · Answer

? - i thought you could only have complex roots in pairs...

welshfella · Answer

-1 is definitely  a root

welshfella · Answer

the greatest power is 4 so there's a total of 4 roots

anonymous · Answer

thanks for the help guys

welshfella · Answer

do 5 and 6 cannot be correct

directrix · Answer

For review:

welshfella · Answer

with Descarts rule you count the changes of sign as you go from left to right in the polynomial 
there is one change in this one

welshfella · Answer

my guess would be 2 real roots and 2 complex

anonymous · Answer

thank you for all your help

welshfella · Answer

yw