syms q t l x y
q=3125.66+0.751*t^4+15.962*t^3+47.229*t^2+718.849*t+0.066*l^2-3.324*l+0.225*t*l^2-11.667*t*l-0.746*t^2*l^2+4.172*t^2*l-0.303*t^3*l;
x=diff(q,t),y=diff(q,l)
x =
751/250*t^3+23943/500*t^2+47229/500*t+6323062672921199/8796093022208+9/40*l^2-11667/1000*l-373/250*t*l^2+1043/125*t*l-909/1000*t^2*l
y =
33/250*l-831/250+9/20*t*l-11667/1000*t-373/250*t^2*l+1043/250*t^2-303/1000*t^3
>> [t l]=solve('751/250*t^3+23943/500*t^2+47229/500*t+6323062672921199/8796093022208+9/40*l^2-11667/1000*l-373/250*t*l^2+1043/125*t*l-909/1000*t^2*l=0',...
'33/250*l-831/250+9/20*t*l-11667/1000*t-373/250*t^2*l+1043/250*t^2-303/1000*t^3=0','t','l')
t =
43.183072734266704069232924070832
-35.990865935880073944190530743398
3.38275144345268187080333349+.75915552768006555999659162*i
14.734900514950506450189819037857-34.127071063123633845729761869531*i
5.907504252049364055985412
14.734900514950506450189819037857+34.127071063123633845729761869531*i
3.38275144345268187080333349-.75915552768006555999659162*i
l=
.27296211968259886787023437829694
.68703559766189964027125046913422
-.70065296463972412640421988298882+4.0442634844937414106709120439943*i
-.18277875124415781446074348150895+.30476607656988256386964964074091e-1*i
-13.099369867753585770049065194964
-.18277875124415781446074348150895-.30476607656988256386964964074091e-1*i
-.70065296463972412640421988298882-4.0442634844937414106709120439943*i
好强大,完全看不懂啊!!