令y=(x²-1)³+1 y′=[(x²-1)³]′+(1)′ =3(x²-1)²(x²-1)′+0 =6x(x²-1)²
y=(x^2-1)^3+1y'=[(x^2-1)^3+1]'=3(x^2-1)^2*(x^2-1)'=6x(x^2-1)^2
