屌 sorry大家 我on9左
我以為b part同c part左邊舊嘢係一樣
我一直係到諗啲sin cos 邊個當x塞
o路人甲o2018-12-05 00:45:54
f(x)=(2x^2+px+1)g(x)=(3x^2+2x+q)h(x) for some polynomial g and h
h(x) = (2x^2+px+1)g(x) / (3x^2+2x+q)
since G.C.D.(2x^2+px+1,3x^2+2x+q) = 1, g(x) is divisible by (3x^2+2x+q) .
Note that 4 = degree of f = degree of g +2, so degree of g = 2
Hence, g(x) = k (3x^2+2x+q) for some non-zero constant k.
so f(x) = k(2x^2+px+1)*(3x^2+2x+q)
comparing the leading coefficient, we have k = 2
會考都無C2018-12-05 00:52:34
第二行h(x)做主項嗰句其實唔寫好啲
唔使煩嗰啲domain問題
夢追人2018-12-05 01:30:11
since G.C.D.(2x^2+px+1,3x^2+2x+q) = 1, g(x) is divisible by (3x^2+2x+q) .
o路人甲o2018-12-05 09:24:22
好似要有euldiean algorithm先証到 當我無講過
高遠搖搖板2018-12-05 11:17:48
euclidean algorithm 算 number theory 唔算 abstract algebra
不能説的咪咪2018-12-05 14:28:51
求救 how many real roots does the equation x^5+2x^3+3x-6=0 have
會考都無C2018-12-05 14:30:03
你試下搵佢啲turning points先
呢隻D完唔難solve
不能説的咪咪2018-12-05 14:31:52
我試下先 係咪一開始都唔洗抽(x-1)?
會考都無C2018-12-05 14:32:40
唔使
就咁D
不能説的咪咪2018-12-05 14:38:37
Sorry會考巴 d完一次大過0之後冇頭緒
會考都無C2018-12-05 14:40:04
咁即係條曲線不斷向上升
得一個real root
高遠搖搖板2018-12-05 15:09:59
啲 non-constant term 全部都 strictly increasing 喎
o路人甲o2018-12-05 19:31:54
f'(x)=5x^4+6x^2+3>0 for all real x
f is strictly increasing.
note that f(x) <f(1) =0 for x <1 and
f(x) >f(1) =0 for x >1
f has only one real root