求不定积分∫1/√(9-4x^2)dx=
问题描述：
求不定积分∫1/√(9-4x^2)dx=
答
换元, 令u = 2x,
∫1/√(9-4x^2)dx = (1/2) ∫1/√(9- u^2) du
= (1/2) * arcsin(u/3) + C
= (1/2) * arcsin( 2x/3) + C