好了今日日討論完有正解
做 polynomial 的 long division 要知道一點
when the divider is of degree n, the highest possible degree of the remainder is n-1
ie. when the divider is of degree 3, the highest possible degree of the remainder is 2
我地又知道如果x-a係factor的話,咁p(a)=0
同埋the remainder is p(b) when p(x) is divided by (x-b)
呢條題目的divider係degree 3
我地可以 let the remainder be px^2+qx+r, where p,q and r are constants.
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p(0)=p*0^2+q*0+r=0
r=0
p(i)=pi^2+qi+r=2i+3
-p+qi+0=2i+3
-p+qi=3+2i
p=-3 and q=2
The remainder is -3x^2+2x when p(x) is divided by x^3+x.
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不過都係想講多次粗口...因為真係冇見過咁的題目...
粗口粗口粗口粗口粗口粗口粗口粗口粗口粗口......... |