1樓:匿名使用者
f=(x-1)(x-2)(x-3)(x-4)(x-5)=(x^2-6x+5)(x^2-6x+8)(x-3)=(x^4-12x^3+49x^2-78x+40)(x-3)=x^5-15x^4+85x^3-225x^2+274x-120
f'(x)=5x^4-60x^3+255x^2-450x+274
2樓:
(uv)'=u'v+v'u
f'=(x-1)'(x-2)(x-3)(x-4)(x-5)+(x-1)((x-2)(x-3)(x-4)(x-5))'
=(x-2)(x-3)(x-4)(x-5)+(x-1)((x-3)(x-4)(x-5)+(x-2)((x-3)(x-4)(x-5))')
=(x-2)(x-3)(x-4)(x-5)+(x-1)((x-3)(x-4)(x-5)+(x-2)((x-4)(x-5)+(x-3)((x-4)+(x+5))))
=(x-2)(x-3)(x-4)(x-5)+(x-1)((x-3)(x-4)(x-5)+(x-2)((x-4)(x-5)+(x-3)(x+1)))
......
3樓:幫個忙好不
笨辦法把多項式乘出來,在求導數
設f(x)=x(x-1)(x-2)(x-3)(x-4)(x-5)(x-6),則f'(x)=?
4樓:匿名使用者
解:已知:f(x)=(x-1)(x-2)(x-3)(x-4)可見:x的最高次項是4次項,
顯然:f'''(x)中x的最高次項是1次項,因此:f'''(x)=0是一元一次方程,
而:一元一次方程只有一個根,
所以:方程f'''(x)=0有一個根。
5樓:紫義卿
我直說,我求不來f'(x)。
但我猜你的題目問的是類似於f'(0)=?之類的。
你可以這樣求:f'(x)=x'[(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)]+x[(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)]'
則f'(0)=(0-1)*(0-2)*(0-3)*(0-4)*(0-5)*(0-6)+0
=720
這只是舉個例子,求f'(1)、f'(2)等等也就是稍微變形就可以了。
如果我猜錯了那就沒辦法了。我不會求f'(x)。
f(x)=x(x-1)(x-2)(x-3)(x-4)(x-5)的導數怎麼求
6樓:匿名使用者
令 f(x)=y=x(x-1)(x-2)(x-3)(x-4)(x-5)
兩邊取對數得:
lny = lnx + ln(x-1) + ln(x-2) + ln(x-3) + ln(x-4)+ ln(x-5)
兩邊求導得:
1/y * y′ = 1/x + 1/(x-1) + 1/(x-2) + 1/(x-3) + 1/(x-4) + 1/(x-5)
f ′(x) = y′ = y
= x(x-1)(x-2)(x-3)(x-4)(x-5) *
= (x-1)(x-2)(x-3)(x-4)(x-5) + x(x-2)(x-3)(x-4)(x-5) + x(x-1)(x-3)(x-4)(x-5) + x(x-1)(x-2)(x-4)(x-5) + x(x-1)(x-2)(x-3)(x-5) + x(x-1)(x-2)(x-3)(x-4)
7樓:匿名使用者
f(x)=x(x-1)(x-2)(x-3)(x-4)(x-5)
lnf(x)=lnx+ln(x-1)+ln(x-2)+ln(x-3)+ln(x-4)+ln(x-5)
f'(x)/f(x)=1/x+1/(x-1)+1/(x-2)+1/(x-3)+1/(x-4)+1/(x-5)
∴f'(x)=f(x)[1/x+1/(x-1)+1/(x-2)+1/(x-3)+1/(x-4)+1/(x-5)]
=x(x-1)(x-2)(x-3)(x-4)(x-5)[1/x+1/(x-1)+1/(x-2)+1/(x-3)+1/(x-4)+1/(x-5)]
已知函式f(x)=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)求f『(2) 導數問題
8樓:我不是他舅
f(x)=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)
f'(x)=(x-1)'(x-2)(x-3)(x-4)(x-5)(x-6)+(x-1)(x-2)'(x-3)(x-4)(x-5)(x-6)+(x-1)(x-2)(x-3)'(x-4)(x-5)(x-6)+(x-1)(x-2)(x-3)(x-4)'(x-5)(x-6)+(x-1)(x-2)(x-3)(x-4)(x-5)'(x-6)+(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)'
=(x-2)(x-3)(x-4)(x-5)(x-6)+(x-1)(x-3)(x-4)(x-5)(x-6)+(x-1)(x-2)(x-4)(x-5)(x-6)+(x-1)(x-2)(x-3)(x-5)(x-6)+(x-1)(x-2)(x-3)(x-4)(x-6)+(x-1)(x-2)(x-3)(x-4)(x-5)
則除了第二項,其他都有x-2
所以x=2時等於0
所以f'(2)=(2-1)(2-3)(2-4)(2-5)(2-6)=24
9樓:匿名使用者
對於f(x)=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)兩邊同時取對數,得
lnf(x)=ln(x-1)+ln(x-2)+ln(x-3)+ln(x-4)+ln(x-5)+ln(x-6)
兩邊同時求導得f'(x)/f(x)=1/(x-1)+1/(x-2)+1/(x-3)+1/(x-4)+1/(x-5)+1/(x-6)
∴f'(x)=f(x)*[1/(x-1)+1/(x-2)+1/(x-3)+1/(x-4)+1/(x-5)+1/(x-6)]
∴ 由導數形式可知,只要式中有(x-2)項,f'(x)那項為0
∴f'(2)=(2-1)(2-3)(2-4)(2-5)(2-6)=24
10樓:匿名使用者
記f(x)=(x-2)g(x),其中g(x)=(x-1)(x-3)(x-4)(x-5)(x-6),得g(2)=4!=24
那麼f'(x)=g(x)+(x-2)g'(x)
則f'(2)=g(2)=24.
11樓:笑年
f(x)=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)
f'(x)=(x-2)(x-3)(x-4)(x-5)(x-6)+(x-1)(x-3)(x-4)(x-5)(x-6)+(x-1)(x-2)(x-4)(x-5)(x-6)+.............
f'(2)=0+1*(-1)*(-2)*(-3)*(-4)+0......+0=24
12樓:匿名使用者
f(x)=)=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)
f'(x) = +
f'(2) = (2-1)(2-3)(2-4)(2-5)(2-6)= 1(-1)(-2)(-3)(-4)
= 24
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