MATLAB Symbolic math toolbox

Hi, I am having troubles with using the symbolic math toolbox to figure out the following:

I have code which doesnt use the symbolic math toolbox which gets the correct graph and also code which attempts to use the symbolic math toolbox but does not work:

Working code without symbolic toolbox:

t = 1:1:10;
s = ((6/5).*(t.^3)-(81/5).*(t.^2)+(252/5).*(t));
velocity = diff(t); %first derivative is velocity
%d/dx of s = 3.6t^2-32.4t+50.4
plot (s)
xlabel('Time (seconds)');
ylabel('Displacement (metres)');

%turning point @ (5,-22.2) on graph

%roots=turning point 

p = [3.6 -32.4 50.4];
r = roots(p);
disp (r)

Non-working code using symbolic math toolbox:

syms t
s = sym(6/5).*(t.^3)-(81/5).*(t.^2)+(252/5).*(t);
v = diff(s); %first derivative is velocity
%d/dx of s = 3.6t^2-32.4t+50.4
fplot (t,v)
xlim([0 10])
ylim([-50 100])
xlabel('Time (seconds)');
ylabel('Displacement (metres)');

%turning point @ (5,-22.2) on graph

%roots=turning point 

p = [3.6 -32.4 50.4];
r = roots(p);
disp (r)

If anyone can assist me in altering the non-working code to achieve the same graph as the working code, that would be greatly appreciated!!

Answer 1

[Ameer Hamza]

fplot() line should be like this

fplot (v, [0 10])

The rest is correct.

[Blake Sewell]

It gives me a much cleaner graph like:

but the graph im after looks like:

[Ameer Hamza]

That was the graph of velocity. If you want the graph of displacement, then use 's'

fplot (s, [0 10])

[Blake Sewell]

Thankyou, appreciate the help!

[Ameer Hamza]

I am glad to be of help!!!