ln（x+sqr（1+x2））求导怎么求
问题描述：
ln（x+sqr（1+x2））求导怎么求
答
=1/[x+√(1+x²)] × [x+√(1+x²)]'
=1/[x+√(1+x²)] × [1+√(1+x²)']
=1/[x+√(1+x²)] × [1+1/2√(1+x²) ×(1+x²)']
=1/[x+√(1+x²)] × [1+x/√(1+x²)]
=1/√(1+x²)