Describe the number and type of roots for the polynomial (how many real and complex?). x 3 + 5x 2 – 4x – 2 = 0
1 x ^3 + 5x^ 2 – 4x – 2 = 0
Note.....if we can add the coefficietnts and get 0, then 1 is a root........
So......1 + 5 - 4 - 2 = 0 ...so 1 is a root....
Performiing some syntthetic division to find the remaining polynomial, we have......
1 [ 1 5 - 4 -2 ]
1 6 2
_____________
1 6 2 0
The remaining polynomial is x^2 + 6x + 2.......
The other two roots can be found by using the quadratic formula....they are
-3 - sqrt(7) and -3 + sqrt (7)
All these roots are real