画的图为什么是从0开始，t=0时候，收益应该不等于0才对

Subscript[\[Pi], m]=(2 a c (t+\[Beta])-c^2 (t+\[Beta])^2+2 t T (-4+2 \[Alpha]^2+(t+\[Beta])^2 \[Gamma]^2)+((-1+\[Theta]) Overscript[a, _]-\[Theta] Q) (2 a+(-1+\[Theta]) Overscript[a, _]-\[Theta] Q))/(-8+4 \[Alpha]^2+2 (t+\[Beta])^2 \[Gamma]^2);
Subscript[\[Pi], r]=-(((-2+\[Alpha]^2) (2 a-c (t+\[Beta]))+a (t+\[Beta])^2 \[Gamma]^2+(-2+\[Alpha]^2+(t+\[Beta])^2 \[Gamma]^2) ((-1+\[Theta]) Overscript[a, _]-\[Theta] Q))^2/(2 (-2+\[Alpha]^2) (-4+2 \[Alpha]^2+(t+\[Beta])^2 \[Gamma]^2)^2));A=Q*\[Theta]+(1-\[Theta])*Overscript[a, _];optw=((-2+\[Alpha]^2) (A+c (t-\[Beta]))+A t (t+\[Beta]) \[Gamma]^2)/(-4+2 \[Alpha]^2+(t+\[Beta])^2 \[Gamma]^2);
opts=((t+\[Beta]) (-A+c (t+\[Beta])) \[Gamma])/(-4+2 \[Alpha]^2+(t+\[Beta])^2 \[Gamma]^2);
optq=(-a+A)/(-2+\[Alpha]^2)+(-A+c (t+\[Beta]))/(-4+2 \[Alpha]^2+(t+\[Beta])^2 \[Gamma]^2);
opte=((-a+A) \[Alpha])/(-2+\[Alpha]^2)+(\[Alpha] (-A+c (t+\[Beta])))/(-4+2 \[Alpha]^2+(t+\[Beta])^2 \[Gamma]^2);vall1={\[Alpha]->0.5,c->0.5,T->1,\[Gamma]->0.7,\[Beta]->0.7,a->120,Overscript[a, _]->100,Q->150,\[Theta]->0.7};
Plot[{Subscript[\[Pi], m](t)/.vall1,Subscript[\[Pi], r](t)/.vall1},{t,0,1},PlotStyle->{Red,Green},PlotLegends->Placed[{M,R},Center],AxesLabel->{"t","收益"}]