21 单选 d ()-|||-( )=dfrac (2t)(1+{t)^4}dt-|||-

证明 :(int )_(x)^1dfrac (dt)(1+{t)^2}=(int )_(1)^dfrac (1{x)}dfrac (dt)(1+{t)^2}(x

3.证明: (int )_(x)^1dfrac (dt)(1+{t)^2}=(int )_(1)^dfrac (1{x)}dfrac (dt)(1+{t)^2}

3.证明: (int )_(x)^1dfrac (dt)(1+{t)^2}=(int )_(1)^dfrac (1{x)}dfrac (dt)(1+{t)^2}

求下列各导数.(1)dfrac (d)(dx)(int )_(0)^xsqrt (1+{t)^4}dt;求下列各导数.(1);

计算下列各导数:-|||-(1) dfrac (d)(dx)(int )_(0)^(x^2)sqrt (1+{t)^2}dt;-|||-(2) dfrac (d

(x)=(int )_(0)^(x^2)dfrac (dt)(sqrt {1+{t)^4}}的单调减少区间是________.的单调减少区间是________.

5.计算下列各导数:-|||-(1) dfrac (d)(dx)(int )_(0)^(x^2)sqrt (1+{t)^2}dt;-|||-(2) dfrac

求曲线=(t)_(2), =2t, =dfrac (1)(2)(t)^2在对应于=(t)_(2), =2t, =dfrac (1)(2)(t)^2点的切线方程和

4.20若已知 (t)arrow F(jomega ) ,试求下列函数的频谱。-|||-(1)tf(2t)-|||-(2) (t-2)f(t)-|||-(3)

求曲线 =dfrac (t)(1+t) =dfrac (1+t)(t) =2t 在对应于 =2t 的点处的切线及法平面方程