y = arcsin(2x+3),先对外层函数arcsin(2x+3)求导数,再乘以内层函数2x+3的导数
y' = 1/√[1 - (2x+3)²] * (2x+3)'
= 1/√(1-4x²-12x-9) * (2)
= 2/√(-4x²-12x-8)
=2/√[4(-x²-3x-2)]
= 1/√(-x²-3x-2)