Trajectory plot wont graph...

I'm fairly new to MATLAB and am trying to write a program to test predicted trajectory paths. My goal is to determine the initial velocity needed for a projectile to reach targets spaced 1 foot apart (3-12ft). I wrote a script using kinematic equations rearranged for v0 and but this inside a for loop with the conditions x = 3:1:12. I can't seem to figure out why it isn't graphing. Any help would be appreciated! Code is listed below.

theta = (75); %degrees
a = -32.2; %ft/s^2
vyFinal = 0; %ft
yInitial = 1; %ft
% Set loop to graph in 1 foot increments from 3 to 12 ft
for x = 3:1:12
    % Find required initial velocity based off distance (varies per loop)
    v0 = sqrt((vyFinal^2)-(2*a*x));
    
    % Determine time of flight
    t = (2*v0.*sin(theta*(pi/180)))/a;
    % Break v0 into components
    vxInitial = v0.*cos(theta*(pi/180));
    vyInitial = v0.*sin(theta*(pi/180));
    % Create graph of trajectories
    x = vxInitial.*t;
    y = vyInitial.*t-0.5*a.*t.^2;
    plot(x,y);
    hold on;
end

Answer 1

[Walter Roberson]

theta = (75); %degrees
a = -32.2; %ft/s^2
vyFinal = 0; %ft
yInitial = 1; %ft
% Set loop to graph in 1 foot increments from 3 to 12 ft
for x = 3:1:12
    % Find required initial velocity based off distance (varies per loop)
    v0 = sqrt((vyFinal^2)-(2*a*x));
    
    % Determine time of flight
    t = (2*v0.*sin(theta*(pi/180)))/a;
    % Break v0 into components
    vxInitial = v0.*cos(theta*(pi/180));
    vyInitial = v0.*sin(theta*(pi/180));
    % Create graph of trajectories
    x = vxInitial.*t;
    y = vyInitial.*t-0.5*a.*t.^2;
    plot(x, y, '-*');
    hold on;
end

plot() only ever creates a line of there are at least two adjacent finite coordinates in one call . Every call to plot() creates one or more line objects that are disconnected from all other line objects. When you only ask to plot one coordinate at a time, you will not get any lines.

In order to get lines, you need to record the x and y values, and plot() the entire record of them afterwards. Or you can use animatedline