limx趋近于0y趋近于0sin(xy)/x求极限.

limx趋近于0y趋近于0sin(xy)/x求极限. 求lim sin(xy)/xy,x趋近于2,y趋近于0 limx趋近于0xlnx limx趋近于0lnarccosx limx趋近于0 (tanx-sinx)/sin^3x limx趋近于0sin(1/x)/(1/x) limx趋近于0sin3x/2x limx趋近于0sin2x/sin5x limx趋近于0,sin5x/tan3x limx趋近于0 tan2x分之x limx趋近于0 sin4x/tan2x= limx趋近于0lnsinx/x limx趋近于0x分之tan2x limx趋近于0x乘cot3x limx趋近于0cscx-cotx= limx趋近于+∞和趋近于负无穷有什么区别?limx趋近于0＋和趋近于0－有什么区别? 证明limx趋近于0,y趋近于0x^3y/x^6+y^2不存在 lim[1+sin(xy)]^(xy)其中x,y均趋近于0