Undefined variable or function 'v'.

I am trying to solve the following second order differential equation;

y'' = (-1/(RC))*y'-(1/(LC))*y

my function is as follows,

function dv = second_order_circuit(t,v)
R = 30;
C = 0.2;
L = 0.8;
dv(1) = v(2);
dv(2) = (-1/(R*C))*dv(1)-(-1/(L*C))*v(2);
end

I cannot figure out why I have the error

Undefined variable or function 'v'

Any help will be greatly appreciated, including what I will need in my command window to plot this over a 20 second period with and initial v(0) = 20 volts.

[Nathan Zanetto]

A simple restart of MatLab has solved the undefined variable issue, I am unable to produce anything though. What do I need in the command window? Thanks.

Answer 1

[Adam]

t = 1:10;
v = 17;

dv = second_order_circuit(t,v);

is an example of what you need on command line, although I have no idea what t and v are in terms of scalar, vector, 2d array, big numbers, small numbers, etc.