(11) y=xe ;(12) y=ln(x 1 x2 ).解 (1)y′=4x 1, y′′=4− 1 . (11) y=xe ;(12) y=ln(x 1 x2 ).解 (1)y′=4x 1, y′′=4− 1 . 发布时间:2025-05-11 02:09:47