x=Acos(wt+phi)
v=x'=-Awcos(wt+phi)
a=v'=x''=Aw2cos(wt+phi)
[list=1][*]he thuc doc lap:

1.x2/A2+v2/(A2.w2)=1
2.v2/(A2.w2)+a2/(A2.w4)=1
*do lech pha:
1.(x,v);(v,a) lech pha nhau pi/2.
2.(x,a) lech pha nhau pi.
**CON LAC LXO NGANG
ki hieu /" :la can,^ :delta
1.w=/"(k/m), T=2pi./"(m/k), a=-kx/m
2. Wð=mv2/2=(mA2w2.sin2(wt+phi))/2
3. Wt=kx2/2
4. W=Wð+Wt=kA2/2=const
***CON LAC LXO DUNG:
1.w=/"(k/m)=/"(g/^lo)
2.^lo=mg/k, a=-kx/m
3. A=(lmax-lmin)/2
4. Lcb=(lmax+lmin)/2
5. Fdhmax=k(^lo+A)
6. Fdhmin:+=0 neu ^lo<=A
+k(^lo-A) neu ^lo=>A
7. Fhp=-kx=-mw2x