SOLUTION: I have a question that I can't figure out. It's 4y to the sixth minus 14y to the fifth minus 144y to the third equals 0. I am supposed to find all six degrees of x. How do I do t

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: I have a question that I can't figure out. It's 4y to the sixth minus 14y to the fifth minus 144y to the third equals 0. I am supposed to find all six degrees of x. How do I do t      Log On


   



Question 71669: I have a question that I can't figure out.
It's 4y to the sixth minus 14y to the fifth minus 144y to the third equals 0. I am supposed to find all six degrees of x. How do I do this. So my teacher say there should be six answers.
Thank you for your help.
Amy

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
4y to the sixth minus 14y to the fifth minus 144y to the third equals 0
4y^6-14y^5-144y^3=0
Factor out 2y^3 to get:
2y^3(2y^3-7y^2-72)=0
y=0 with multiplicity 3
I graphed the cubic and found a root at approximately y=-4.9620881
The other two zeroes may be complex numbers:not sure.
Cheers,
Stan H.