matlab 出错Error using ==> mrdivide Matrix dimensions must agr

matlab 出错Error using ==> mrdivide Matrix dimensions must agree.clear;clc;syms y0 t;hold on;axis([1,90,0,3]);t=1:775;t=t/30.93;y0=15274.6-(2670+0.2766*t.^2);y0=19580/y0;plot(t,y0,'-b','linewidth',3);图画不出来,请高手看看这哪里有问题.