17da4243ce1def6.jpg=2sin（314t+10°）A与[img=10x17]17da4243d8849cc.jpg[/img]=-4sin（314t+95°）A的相位差[img=15x14]17da426d14450d1.jpg[/img]－[img=15x14]17da426d1dc5113.jpg[/img]是
A: 95°
B: ﹣85°
C: 85°
A: 95°
B: ﹣85°
C: 85°
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))
- 17da4243ce1def6.jpg=3sin(314t+50°), [img=10x17]17da4243d8849cc.jpg[/img]=-4sin(314t+95°)A的[img=10x17]17da4243ce1def6.jpg[/img]与[img=10x17]17da4243d8849cc.jpg[/img]的相位差[img=46x16]17da4243eaddf12.jpg[/img]是 A: 45° B: -45° C: 135°
- 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)
- i1=3sin（314t+10°）A与i2=-4sin（314t+95°）A的相位差[img=56x23]1803a298233f3e1.png[/img]是（ ） A: 95° B: -85° C: 85° D: 115°
- i1=3sin（314t+10°）A与i2= - 4sin（314t+95°）A的相位差[img=59x23]1803a24fb6a2984.png[/img]是（ ） A: -85° B: 115° C: 85° D: 95°