(多选)下列各方程中（仅x、Q是时间函数）可表示为简谐振动形式的是
未知类型：{'options': ['X=A sin（ωt+[img=10x14]17e435cd2fb1476.jpg[/img]）', ' X=A cos（ωt+[img=10x14]17e435cd2fb1476.jpg[/img]）', ' X=A [img=25x16]17e4492025c4016.jpg[/img]cos（ωt+[img=10x14]17e435cd2fb1476.jpg[/img]）', ' (d²Q)/(dt²)+Q/(LC)=0 (L和C是常量)'], 'type': 102}
未知类型：{'options': ['X=A sin（ωt+[img=10x14]17e435cd2fb1476.jpg[/img]）', ' X=A cos（ωt+[img=10x14]17e435cd2fb1476.jpg[/img]）', ' X=A [img=25x16]17e4492025c4016.jpg[/img]cos（ωt+[img=10x14]17e435cd2fb1476.jpg[/img]）', ' (d²Q)/(dt²)+Q/(LC)=0 (L和C是常量)'], 'type': 102}
举一反三
- 求不定积分[img=132x48]17da6537fc8dad6.png[/img]； （ ） A: -(4*(cos(x/2)/2 + 2*sin(x/2)))/(17*exp(2*x)) B: (4*(sin(x/2)/2 + 2*sin(x/2)))/(17*exp(2*x)) C: (4*(cos(x/2)/2 + 2*sin(x/2)))/(17*exp(2*x)) D: (4*(cos(x/2)/2 + 2*cos(x/2)))/(17*exp(2*x))
- 4.9一质点作简谐振动, 其速度随时间变化的规律为v=-[img=9x11]17da3b8fae866c3.jpg[/img]Acos[img=9x11]17da3b8fae866c3.jpg[/img]t, 则质点的振动方程为 未知类型：{'options': ['x=Asin[img=9x11]17da3b8fae866c3.jpg[/img]t', ' x=Acos[img=9x11]17da3b8fae866c3.jpg[/img]t', ' x=Asin([img=9x11]17da3b8fae866c3.jpg[/img]t+[img=8x11]17da3b6dd8d7415.jpg[/img])', ' x=Acos([img=9x11]17da3b8fae866c3.jpg[/img]t+[img=8x11]17da3b6dd8d7415.jpg[/img])'], 'type': 102}
- 求微分方程[img=143x21]17da5f14490e50e.png[/img]的通解,实验命令为(). A: dsolve(D2y-2*Dy+5*y=sin(2*x),x)ans =exp(x)*sin(2*x)*C2+exp(x)*cos(2*x)*C1+1/17*sin(2*x)+4/17*cos(2*x) B: dsolve('D2y-2*Dy+5*y=sin(2*x)','x')ans =cos(2*x)*(sin(4*x)/17 - cos(4*x)/68 + 1/4) - sin(2*x)*(cos(4*x)/17 + sin(4*x)/68) + C1*cos(2*x)*exp(x) - C2*sin(2*x)*exp(x) C: dsolve(D2y-2*Dy+5*y=sin(2*x),'x','y')ans =exp(x)*sin(2*x)*C2+exp(x)*cos(2*x)*C1+1/17*sin(2*x)+4/17*cos(2*x)
- 设\(z = f(x,y)\)，\(x = \sin t\)，\(y = {t^3}\)，则全导数\( { { dz} \over {dt}} = \) A: \({f'_x} \sin t+ 3{t^2}{f'_y}\) B: \({f'_x} \cos t+ {t^2}{f'_y}\) C: \({f'_x} \cos t+ 3{t^2}{f'_y}\) D: \({f'_y} \cos t+ 3{t^2}{f'_x}\)
- 下列的推理结构中哪个是正确的推理形式()。 未知类型：{'options': ['([img=8x14]17e4385a99bb660.jpg[/img] x)P(x) ∧ ([img=8x14]17e4385a99bb660.jpg[/img]x)Q(x) → ([img=8x14]17e4385a99bb660.jpg[/img]x)(P(x) ∧Q(x))', ' ([img=8x14]17e4385a99bb660.jpg[/img] x)P(x) → ([img=8x14]17e4385a99bb660.jpg[/img]x)(P(x) ∧ Q(x))', ' ([img=8x14]17e4385a99bb660.jpg[/img]x)(P(x) ∨ Q(x)) → ([img=8x14]17e4385a99bb660.jpg[/img]x)P(x) ∨([img=8x14]17e4385a99bb660.jpg[/img]x)Q(x)', ' ([img=8x14]17e4385a99bb660.jpg[/img]x)(P(x)∨ Q(x)) → ([img=8x14]17e4385a99bb660.jpg[/img] x)P(x) ∧ ([img=8x14]17e4385a99bb660.jpg[/img] x)Q(x)'], 'type': 102}