y=(1-x)(1-x^2)^2(1-x^3)^3求導(用對數)謝謝

y=(1-x)(1-x^2)^2(1-x^3)^3求導(用對數)謝謝


lny=ln(1-x)+2ln(1-x^2)+3ln(1-x^3)兩邊取對數得y′/y=-1/(1-x)+2/(1-x^2)*(-2x)+3/(1-x^3)*(-3x^2)=-1/(1-x)-4x/(1-x^2)-9x^2/(1-x^3)y′=-[1/(1-x)+4x/(1-x^2)+9x^2/(1-x^3)]y=-[(1-x^2)^2(1-x^3)…



y=2xsin(2x+5),求函數的導數


由y=f*g(f,g是兩個函數)的導數公式可知:
y=f'*g+f*g'
又由f(g)'=f'*g'
所以y'=(2x)'*sin(2x+5)+2x*[sin(2x+5)]'
=2sin(2x+5)+2xcos(2x+5)*2
=2sin(2x+5)+4xcos(2x+5)