例6求y=x3-2x2+sinx的导数 解y=3x2-4x+cosx. 例7求y=x3nx的导数 解y=(x3lx (x3)y·lnx+x(lnx) 3x2·lnx+x 3x Inx+x Economic-mathematics 31-11 Wednesday, February 24 2021Economic-mathematics 31 - 11 Wednesday, February 24, 2021 例6 2 sin . 求 y = x 3 − x 2 + x的导数 解 2 y = 3x − 4x 例7 ln . 求 y = x 3 x的导数 解 ( ln ) 3 y = x x  + cos x. ( ) ln (ln ) 3 3 = x   x + x  x  x x x x 1 3 ln 2 3 =  +  2 2 = 3x ln x + x