【题目】 dfrac (9)(20)= __

[题目]按规律填数:1, dfrac (1)(3).dfrac (1)(9),dfrac (1)(27) ,-|||-() ,.-|||-

[题目]求椭圆 dfrac ({x)^2}(4)+dfrac ({y)^2}(9)=1 在点 (1,dfrac (3sqrt {3)}(2)) 处的法线方-||

11设 9.ipg-|||-OA dfrac (5)(9)-|||-CB dfrac (1)(9)-|||-oc dfrac (4)(9)-|||-dfrac

【题目】-|||-gt dfrac (1)(x)

[题目]-|||-.将函数 (x)=dfrac (x)(9+{x)^2} 展开成x的幂级数.

[题目] int dfrac (dx)(xln x)

[题目] lim _(xarrow 0)(dfrac (1)({x)^2}-dfrac (1)(xsin x))

[题目] int xcos dfrac (x)(2)dx

[题目] int xcos dfrac (x)(2)dx

[题目]-|||-求曲线 ^dfrac (2{3)}+(y)^dfrac (2{3)}=(a)^dfrac (2{3)} 在点 (dfrac (sqrt {2)