SOLUTION: Find the roots of the polynomial equation. -x3 + 5x2 - 11x + 55 = 0 A) i√11, -1√11,-5 B) √11,-√11,5 C) i√11,-5 D) i√11,-i√11,5

Algebra ->  Equations -> SOLUTION: Find the roots of the polynomial equation. -x3 + 5x2 - 11x + 55 = 0 A) i√11, -1√11,-5 B) √11,-√11,5 C) i√11,-5 D) i√11,-i√11,5      Log On


   

Question 669022: Find the roots of the polynomial equation.
-x3 + 5x2 - 11x + 55 = 0
A) i√11, -1√11,-5
B) √11,-√11,5
C) i√11,-5
D) i√11,-i√11,5
Found 2 solutions by lynnlo, ewatrrr:
Answer by lynnlo(4176) About Me  (Show Source):
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

y = -x3 + 5x2 - 11x + 55   ||x = 5 one root  -125 + 125 - 55 + 55 = 0

using Synthetic Divsion

5	-1	5	-11	55

 	 	-5	0	-55

 	-1	0	-11	0

results in:

 -x^2 - 11 = 0

 x^2 + 11 = 0

   x^2 = -11

   x = ± i√11

roots are:  i√11,-i√11,5