getting y1(i)=traj​ectory(x1(​i),v0,thet​a) presents an error in matlab

Question

x=0;
y=4;
v0=80;
theta=50:10:90;
g=9.8;
disp(\'part a\')
 
 
 
 
% a) and b)
 
 
fprintf("Theta(d)\\t height(m)\\t Range(m)\\n");
for t = 1:length(theta)
p