How to plot this line and specified point

In addition to the point on the graph that shows up, I'd like to also have the line of the equation show up on the graph as well. I have tried using hold on and hold off and a couple other ways, but I cannot figure it out

prompt = 'Time of flight? (s) ';
t = input(prompt);

if (t <= 45)
    h = 15*t.^2;
    fprintf('Altitude: %dm\n\n', h) 
    v = 30*t;
    fprintf('Velocity: %dm/s\n\n', v);
    
    figure(1)
    subplot(2,1,1)
    plot(t, h, 'o'), xlabel('Time (s)'), ylabel('Altitude (m)'), title('Altitude vs Time')
    subplot(2,1,2)
    plot(t, v,'o'), xlabel('Time (s)'), ylabel('Velocity (m/s)'), title('Velocity vs Time')
    
    
elseif (t < 117.5)
    h = 30375 + (1350*t) + 0.5*(-11.5)*t.^2;
    fprintf('Altitude: %dm\n\n', h )     
    v = 1350 - 11.5*t;
    fprintf('Velocity: %dm/s\n\n', v);
    
    figure(2)
    subplot(2,1,1)
    plot(t, h,'o'), xlabel('Time (s)'), ylabel('Altitude (m)'), title('Altitude vs Time')
    subplot(2,1,2)
    plot(t, v,'o'), xlabel('Time (s)'), ylabel('Velocity (m/s)'), title('Velocity vs Time')
    
    
end

Answer 1

[Davide Masiello]

prompt = 'Time of flight? (s) ';
t = input(prompt);
tx = t-5:t+5;

if (t <= 45)
    h = @(x) 15*x.^2;
    fprintf('Altitude: %dm\n\n', h(t)) 
    v = @(x) 30*x;
    fprintf('Velocity: %dm/s\n\n', v(t));
    
    figure(1)
    subplot(2,1,1)
    plot(t,h(t),'o',tx,h(tx)), xlabel('Time (s)'), ylabel('Altitude (m)'), title('Altitude vs Time')
    subplot(2,1,2)
    plot(t,v(t),'o',tx,v(tx)), xlabel('Time (s)'), ylabel('Velocity (m/s)'), title('Velocity vs Time')
        
elseif (t < 117.5)
    h = @(x) 30375 + (1350*x) + 0.5*(-11.5)*x.^2;
    fprintf('Altitude: %dm\n\n', h(t))     
    v = @(x) 1350 - 11.5*x;
    fprintf('Velocity: %dm/s\n\n', v(t));
    
    figure(2)
    subplot(2,1,1)
    plot(t,h(t),'o',tx,h(tx)), xlabel('Time (s)'), ylabel('Altitude (m)'), title('Altitude vs Time')
    subplot(2,1,2)
    plot(t,v(t),'o',tx,v(tx)), xlabel('Time (s)'), ylabel('Velocity (m/s)'), title('Velocity vs Time')
    
end

[RetiredCheetoXI]

Awesome! Thanks for your help. Would you be able to explain what you did on line 3?

[Davide Masiello]

I just created a vector of times that spans around your input time.

If the code works and you are satisfied with the answer, please accept it. I will reply to any further questions anyways.