高数f(x)=(x-1)(x+1)(x+1)(x+1)求导怎么求

问题描述:

高数f(x)=(x-1)(x+1)(x+1)(x+1)求导怎么求

你可以拆开求:f(x)=(x^2-1)(x^2+2x+1)=x^4+2x^3-2x-1
f‘(x)=4x^3+6x^2-2

X 的平方——1再乘以X+1的平方然后再求导呗
结果是4X^3+6X^2--2

f(x)=(x-1)(x+1)(x+1)(x+1)
=(x²-1)(x²+2x+1)
=x⁴+2x³+x²-x²-2x-1
=x⁴+2x³-2x-1
∴f′(x)=4x³+6x²-2

楼上很好的答案

取自然对数
lny=ln[(x-1)(x+1)(x+1)(x+1)]
=ln(x-1)+3ln(x+1)
两边求导得
y'/y=1/(x-1)+3/(x+1)
y'=[1/(x-1)+3/(x+1)]*y=[1/(x-1)+3/(x+1)]*(x-1)(x+1)(x+1)(x+1)

f(x)=(x-1)(x+1)^3
f'(x) = (x+1)^3+3x(x-1)

=x^-1(x+1)^
=x^-1(x^+2x+1)
=x的四次方+2乘以x的三次方-2x-1
求导=4乘以x的三次方+6x^-2