求函数[img=107x38]17da6537b12a2e0.png[/img]的导数； ( ) A: 2*x*sin(1/x) - sin(1/x) B: 2xsin(1/x) - cos(1/x) C: 2*x*sin(1/x) - cos(1/x) D: 2*x*cos(1/x) - cos(1/x)

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2022-06-03 问题

求函数[img=107x38]17da6537b12a2e0.png[/img]的导数； ( ) A: 2xsin(1/x) - sin(1/x) B: 2xsin(1/x) - cos(1/x) C: 2xsin(1/x) - cos(1/x) D: 2xcos(1/x) - cos(1/x)

2022-06-07 问题

$\int {{1 \over {3 + 5\cos x}}} dx = \left( {} \right)$ A: ${1 \over 4}\ln \left| {{{2\cos x + \sin x} \over {2\cos x - \sin x}}} \right| + C$ B: ${1 \over 4}\ln \left| {{{2\cos {x \over 2} + \sin {x \over 2}} \over {2\cos {x \over 2} - \sin {x \over 2}}}} \right| + C$ C: $\ln \left| {{{\cos {x \over 2} + \sin {x \over 2}} \over {\cos {x \over 2} - \sin {x \over 2}}}} \right| + C$ D: $\ln \left| {{{\cos x + \sin x} \over {\cos x - \sin x}}} \right| + C$

$\int {{1 \over {3 + 5\cos x}}} dx = \left( {} \right)$ A: ${1 \over 4}\ln \left| {{{2\cos x + \sin x} \over {2\cos x - \sin x}}} \right| + C$ B: ${1 \over 4}\ln \left| {{{2\cos {x \over 2} + \sin {x \over 2}} \over {2\cos {x \over 2} - \sin {x \over 2}}}} \right| + C$ C: $\ln \left| {{{\cos {x \over 2} + \sin {x \over 2}} \over {\cos {x \over 2} - \sin {x \over 2}}}} \right| + C$ D: $\ln \left| {{{\cos x + \sin x} \over {\cos x - \sin x}}} \right| + C$

2022-05-27 问题

求下列不定积分.[tex=7.286x2.643]28VI4S//fW038PiMAbBHktfj3FfJYocy4+TgcP5gH+6DCjcL5MVe5w4GLCJx2oaC[/tex].腺由于 $\sin ^{4} x+\cos ^{4} x=\left(\cos ^{2} x-\sin ^{2} x\right)^{2}+2 \sin ^{2} x \cos ^{2} x$$=\cos ^{2} 2 x+\frac{1}{2} \sin ^{2} 2 x$原式 $=\int \frac{\mathrm{d} x}{\cos ^{2} 2 x+\frac{1}{2} \sin ^{2} 2 x}$

求下列不定积分.[tex=7.286x2.643]28VI4S//fW038PiMAbBHktfj3FfJYocy4+TgcP5gH+6DCjcL5MVe5w4GLCJx2oaC[/tex].腺由于 $\sin ^{4} x+\cos ^{4} x=\left(\cos ^{2} x-\sin ^{2} x\right)^{2}+2 \sin ^{2} x \cos ^{2} x$$=\cos ^{2} 2 x+\frac{1}{2} \sin ^{2} 2 x$原式 $=\int \frac{\mathrm{d} x}{\cos ^{2} 2 x+\frac{1}{2} \sin ^{2} 2 x}$

2022-07-26 问题

$\int {{{x\cos x} \over {{{\sin }^3}x}}} dx = \left( {} \right)$ A: $ - {x \over {2{{\sin }^2}x}} - {1 \over 2}\tan x + C$ B: $ - {x \over {2{{\sin }^2}x}} - {1 \over 2}\cot x + C$ C: $ - {x \over {2{{\cos }^2}x}} - {1 \over 2}\cot x + C$ D: $ - {x \over {2{{\cos }^2}x}} - {1 \over 2}\tan x + C$

$\int {{{x\cos x} \over {{{\sin }^3}x}}} dx = \left( {} \right)$ A: $ - {x \over {2{{\sin }^2}x}} - {1 \over 2}\tan x + C$ B: $ - {x \over {2{{\sin }^2}x}} - {1 \over 2}\cot x + C$ C: $ - {x \over {2{{\cos }^2}x}} - {1 \over 2}\cot x + C$ D: $ - {x \over {2{{\cos }^2}x}} - {1 \over 2}\tan x + C$

2022-07-26 问题

17e0b849d3a4a3b.jpg,计算[img=19x34]17e0ab14a855463.jpg[/img]的实验命令为（）. A: syms x; f=diff((1+sin(x)^2)/cos(x),1)f=2sin(x) + (sin(x)(sin(x)^2 + 1))/cos(x)^2 B: f=diff((1+sinx^2)/cosx,1)f=1/2/x^(1/2)/(1-x)^(1/2) C: syms x;f=diff((1+sinx^2)/cosx,1)f=2sin(x) + (sin(x)(sin(x)^2 + 1))/cos(x)^2

17e0b849d3a4a3b.jpg,计算[img=19x34]17e0ab14a855463.jpg[/img]的实验命令为（）. A: syms x; f=diff((1+sin(x)^2)/cos(x),1)f=2*sin(x) + (sin(x)*(sin(x)^2 + 1))/cos(x)^2 B: f=diff((1+sinx^2)/cosx,1)f=1/2/x^(1/2)/(1-x)^(1/2) C: syms x;f=diff((1+sinx^2)/cosx,1)f=2*sin(x) + (sin(x)*(sin(x)^2 + 1))/cos(x)^2

2022-06-09 问题

设$z = \int_ { { x^2}}^y { { e^t}\sin t} dt$，则${z_{xx}=}$ A: $2{e^ { { x^2}}}\left[ {\left( {1 + 2{x^2}} \right)\sin {x^2} + 2{x^2}\cos {x^2}} \right]$ B: $ - 2{e^ { { x^2}}}\left[ {\left( {1 + 2{x^2}} \right)\sin {x^2} - 2{x^2}\cos {x^2}} \right]$ C: $ - 2{e^ { { x^2}}}\left[ {\left( {1 + 2{x^2}} \right)\sin {x^2} + 2{x^2}\cos {x^2}} \right]$ D: $ - 2{e^ { { x^2}}}\left[ {\left( {1 + 2{x^2}} \right)\cos {x^2} + 2{x^2}\sin {x^2}} \right]$

设$z = \int_ { { x^2}}^y { { e^t}\sin t} dt$，则${z_{xx}=}$ A: $2{e^ { { x^2}}}\left[ {\left( {1 + 2{x^2}} \right)\sin {x^2} + 2{x^2}\cos {x^2}} \right]$ B: $ - 2{e^ { { x^2}}}\left[ {\left( {1 + 2{x^2}} \right)\sin {x^2} - 2{x^2}\cos {x^2}} \right]$ C: $ - 2{e^ { { x^2}}}\left[ {\left( {1 + 2{x^2}} \right)\sin {x^2} + 2{x^2}\cos {x^2}} \right]$ D: $ - 2{e^ { { x^2}}}\left[ {\left( {1 + 2{x^2}} \right)\cos {x^2} + 2{x^2}\sin {x^2}} \right]$

2022-06-06 问题

cos(x)cos(x/2)cos(x/4)*cos(x/8).cos(x/(2^(n-1))

cos(x)*cos(x/2)*cos(x/4)*cos(x/8).cos(x/(2^(n-1))

2022-06-15 问题

常微分方程[img=243x26]1802e4d57c1aad8.png[/img]的解为： A: exp(-x)sin(3^(1/2)x)C2+exp(-x)cos(3^(1/2)x)C1-1/4cos(2x)，C1、C2为任意常数 B: exp(-2x)cos(3^(1/2)x)C2+exp(-2x)cos(3^(1/2)x)C1-1/4sin(2x)，C1、C2为任意常数 C: exp(-3x)sin(3^(1/2)x)C2+exp(-3x)sin(3^(1/2)x)C1-1/4sin(2x)，C1、C2为任意常数 D: exp(-4x)sin(3^(1/2)x)C2-exp(-4x)cos(3^(1/2)x)C1-1/4cos(2x)，C1、C2为任意常数

常微分方程[img=243x26]1802e4d57c1aad8.png[/img]的解为： A: exp(-x)*sin(3^(1/2)*x)*C2+exp(-x)*cos(3^(1/2)*x)*C1-1/4*cos(2*x)，C1、C2为任意常数 B: exp(-2x)*cos(3^(1/2)*x)*C2+exp(-2x)*cos(3^(1/2)*x)*C1-1/4*sin(2*x)，C1、C2为任意常数 C: exp(-3x)*sin(3^(1/2)*x)*C2+exp(-3x)*sin(3^(1/2)*x)*C1-1/4*sin(2*x)，C1、C2为任意常数 D: exp(-4x)*sin(3^(1/2)*x)*C2-exp(-4x)*cos(3^(1/2)*x)*C1-1/4*cos(2*x)，C1、C2为任意常数

2022-06-17 问题

函数$y = \sin {1 \over x}$的导数为（）. A: ${1 \over { { x^2}}}\sin {1 \over x}$ B: $ - {1 \over { { x^2}}}\sin {1 \over x}$ C: $ - {1 \over { { x^2}}}\cos {1 \over x}$ D: ${1 \over { { x^2}}}\cos {1 \over x}$

函数$y = \sin {1 \over x}$的导数为（）. A: ${1 \over { { x^2}}}\sin {1 \over x}$ B: $ - {1 \over { { x^2}}}\sin {1 \over x}$ C: $ - {1 \over { { x^2}}}\cos {1 \over x}$ D: ${1 \over { { x^2}}}\cos {1 \over x}$

2022-06-04 问题

求函数[img=192x40]17da653862ff7b6.png[/img]的导数； ( ) A: cos(x)/sin(x) - cot(x)(cot(x)^2 + 1) B: cos(x)/sin(x) C: cot(x)(cot(x)^2 + 1) D: cos(x)/sin(x) - cot(x)*(cot(x)^2 + 1)+cot(x)

求函数[img=192x40]17da653862ff7b6.png[/img]的导数； ( ) A: cos(x)/sin(x) - cot(x)*(cot(x)^2 + 1) B: cos(x)/sin(x) C: cot(x)*(cot(x)^2 + 1) D: cos(x)/sin(x) - cot(x)*(cot(x)^2 + 1)+cot(x)

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