defferentiation

The answer is as follows :


圖片參考：http://dc700.4shared.com/img/r0M1etPUba/s7/14439ef8b60/2014-02-16D.png?async&rand=0.7350721142872727


http://dc700.4shared.com/img/r0M1etPUba/s7/14439ef8b60/2014-02-16D.png?async&rand=0.7350721142872727

2014-02-16 21:29:22 補充：
Sorry, there is a type. All (2x - 1) should be (2x + 1).

郭老師 和 pingshek 都是好好的人，我一早就知道了～

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y = (x-2)⁴(2x+1)³

dy/dx = (x-2)⁴[d(2x+1)³/d(2x+1)][d(2x+1)/dx] + (2x+1)³[d(x-2)⁴/d(x-2)][d(x-2)/dx]

= (x-2)⁴[3(2x+1)²][2]+(2x+1)³[4(x-2)³][1]
=6(x-2)⁴(2x+1)²+4(2x+1)³(x-2)³
=2(x-2)³(2x+1)²[3(x-2)+2(2x+1)]
=2(x-2)³(2x+1)²[3x-6+4x+2]
=2(x-2)³(2x+1)²(x-4)

2014-02-16 17:14:17 補充：
The last step is wrong

=2(x-2)³(2x+1)²[3x-6+4x+2]
=2(x-2)³(2x+1)²(x-4)

should be

=2(x-2)³(2x+1)²[3x-6+4x+2]
=2(x-2)³(2x+1)²(7x-4)

2014-02-16 21:24:33 補充：
樓上好睇D，但留意第 3 行到第 4 行，可能一時不小心，(2x+1)變了(2x-1)。
但好有心地為你解答，好人一個啦！選他做最佳吧！