@Basia: Dzielimy W(x) przez x−1
x
3 + a
2x
2 − 4ax + 7 : (x−1) = x
2 + (a
2+1)x + (a
2−4a+1)
−x
3 + x
2
−−−−−−−−−−−−−−−−−−−−−−−−
(a
2+1)x
2 − 4ax + 7
− (a
2+1)x
2 + (a
2+1)x
−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−
(a
2−4a+1)x + 7
−(a
2−4a+1)x + (a
2−4a+1)
−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−
a
2−4a+1+7 = a
2−4a+8
reszta to a
2−4a+8 czyli
a
2 − 4a + 8 = 4
a
2 − 4a + 4 = 0
Δ = (−4)
2 − 4*1*4 = 16−16=0
a=2
dla a=2
W(x) = x
3 + 4x
2 − 8x + 7
x
3 + 4x
2 − 8x + 7 : (x
2+x+1) = x + 3
−x
3 − x
2 − x
−−−−−−−−−−−−−−−−−−
3x
2 − 9x + 7
−3x
2 − 3x − 3
−−−−−−−−−−−−−−−−−−−−
−12x + 4
x
3 + 4x
2 − 8x + 7 = (x
2+x+1)*(x+3) −12x + 4