微积分第二章习题参考答案第二章一元函数微分学习题答案§2.1导数的概念(19-20)000001.(),2(),(0);;()();4fxfxffxxfx一13125;(),();223233yxyx米秒.可微可导连续极限存在.1.|sin|0.yxx二在处不可导2.1,0,x当时函数在处可导1,0x当时函数在处不可导...(1)(10)1,(10),fffab三解1;ba2101(1)lim2,1xxfx又10()1(1)lim1xaxbfx2,11.aba10(1)1lim,1xaxaax..四证明(),()().fxfxfx为偶函数0()(0)(0)limxfxffx0()(0)lim(0).xfxffx(0)0.f0()(0)limxfxfx..五证明200,00200(),(),yaxyyxxx设切点为0000:(),yyyxxx切线方程为其截距式为001,22xyxy切线与两坐标轴构成的三角形面积2001|2||2|22Sxya为常数,与切点无关.§2.2求导法则(21-22)22.1.2cossec,3cos2sec;xxxx一sin22.cos,;1xxeee222cos2sin213.,(cos33sin3);2xxxxexxxarctan14.csc,;2(1)e5.sec;t226.,(1);1xxcx01lim(cos)(sin)1.2xfxxx2217.,(ln(1)).1xxcx08.lim(cos)xdfxdx1.(1).二.解2211(1)11xyxxxx2221.1(1)xxxx21(2)3sec(ln)sec(ln)tan(ln)yxxxx33sec(ln)tan(ln).xxx2ln(1)ln,yxxx21sin2111(3)(2sin)cos()vuevvv21sin212sin.vevv222(cosh(ln))(sinh(ln))1(cosh(ln))xxyxxsinh(ln)(4)(ln)cosh(ln)xythxx21.(cosh(ln))xx2..(),(),fxfx解可导连续201(0)lim(1).(0),xfbxbfa又220000(1)1(1)1(0)limlim0,xxbxxfxx0.,0,1,()aabfx综上所述当时处处可导.()()()()();xxfxxfxdyefeefeefxdx3.解.(1)2(2)(sin)2sincosdyfxxxdx22[(sin)(cos)]sin2.fxfxx2(cos)2cos(sin)fxxx21(3)();1()yfxfx(4)(sin)coscos[()]().yfxxfxfx1000014..()lim()lim1(0),1xxxfxfe解一()0,(0).fxxf在处不连续不存在100101()(0)limxxefx二(0).f不存在1001lim,(1)xxxe..(1)(),()(),fxfxfx三证明设为偶函数则()(),()(),fxfxfxfx();fx即为奇函数(2)(),()(),fxfxfx...