问题描述： 求y=ln(a^2-x^2)的二阶导数 1个回答 分类：数学 2014-10-17 问题解答： 我来补答 y=ln(a²-x²)dy/dx=dln(a²-x²)/d(a²-x²)*d(a²-x²)/dx=1/(a²-x²)*(-2x)=-2x/(a²-x²)d²y/dx²=-2*1/(a²-x²)²*[(a²-x²)*1-x*(-2x)]=-2/(a²-x²)²*(a²-x²+2x²)=-2/(a²-x²)²*(a²+x²)=-2(a²+x²)/(a²-x²)²=-1/(a+x)²-1/(a-x)² 展开全文阅读
