复合函数应该用链式法则求导：若y=g(u),u=f(x),则dy/dx=dy/du*du/dx
y=sin^5x
dy/dx=dsin^5x/dsinx*dsinx/dx
=5sin ⁴xcosx
y=cos(4x+3)
dy/dx=dcos(4x+3)/d(4x+3)*d(4x+3)/dx
=-sin(4x+3)*4
=-4sin(4x+3)
求y=sin^5x ,y=cos(4x+3) 的导数,
复合函数应该用链式法则求导：若y=g(u),u=f(x),则dy/dx=dy/du*du/dx
y=sin^5x
dy/dx=dsin^5x/dsinx*dsinx/dx
=5sin ⁴xcosx
y=cos(4x+3)
dy/dx=dcos(4x+3)/d(4x+3)*d(4x+3)/dx
=-sin(4x+3)*4
=-4sin(4x+3)