derivative of ln & e

2009-03-03 10:38 am
y= e^(x^3) * ln x^2

the derivative is e^(x^3) * [(3x^2 ln x^2) +2x^-1]

I assume this is the product rule, right? And, I tried to solve it according to the product rule, but it doesn't work. please help!!!

thx in advance!
更新1:

I have another question: f(x) = (1-e^x) / x^2 the derivative is (e^x(1-x) -1) / x^2 I used quotient rule but I can't find the answer. please show me the procedure...

回答 (2)

2009-03-03 8:02 pm
✔ 最佳答案
Question 1


y = e^(x^3) * ln x^2
dy/dx = {d[e^(x^3)] / dx}(ln x^2) + {d(ln x^2) / dx}[e^(x^3)]
= 3x^2[e^(x^3)](ln x^2) + (2x / x^2)[e^(x^3)]
= [e^(x^3)][3x^2(ln x^2) + (2 / x)]




Question 2

should be f(x) = (1 - e^x) / x, NOT x^2
f'(x) = {[d(1 - e^x) / dx]x - (dx / dx)(1 - e^x)} / x^2
= [-xe^x - (1 - e^x)] / x^2
= (-xe^x - 1 + e^x)] / x^2
= [e^x(1 - x) - 1] / x^2
參考: knowledge
2009-03-03 5:28 pm
[f(x)g(x)]'=f(x)'g(x)+f(x)g(x)'
[f(g(x))]'=f'(g(x))+g'(x)
1.
令f(x)=e^(x^3)
g(x)=lnx^2
f(x)'=3x^2×e^(x^3)
g(x)'=(1/x^2)×2x=2/x
∴y=[3x^2×e^(x^3)]×[lnx^2]+[e^(x^3)]×[2/x]
  =e^(x^3)× [(3x^2 ln x^2) +2/x]

第2題, sorry,我也求不出你給的答案
如果我算出來會馬上補充的~^^
參考: Meself


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