Question 320897: I need to sketch this polynomial function.... x^3-5x^2+2x+8. How do I factor this. Can't group it... ? Answer by toidayma(44) (Show Source):
You can put this solution on YOUR website! If you can see that x = -1 is one root, it is easy now :-)
x^3 - 5x^2 +2x + 8 = x^3 + x^2 - 6x^2 - 6x + 8x - 8 = x^2(x+1) - 6x(x+1) + 8(x+1) = (x+1)(x^2 - 6x +8)
Easy, right?