求下列函数的导数 .y=ln(cos(10-3x²））

y'=[cos(10-3x^2)]'/cos(10-3x^2)=-sin(10-3x^2)*(10-3x^2)'/cos(10-3x^2)=-sin(10-3x^2)*(-6x)/cos(10-3x^2)=6xtan(10-3x^2)