why iam getting error

tf1 = tf(1, 0.08 1):

Invalid expression. Check for missing multiplication operator, missing or unbalanced delimiters, or other syntax error. To construct matrices, use brackets instead of parentheses.

tf2 = tf(1,0.03 1):
tf_series = tf1 * tf2

Answer 1

[Walter Roberson]

The colon operator always has to be followed by a second parameter, except when it is being used as the sole index to an array.

tf1 = tf(1, [0.08 1]);
tf2 = tf(1, [0.03 1]);
tf_series = tf1 * tf2

tf_series =
 
             1
  -----------------------
  0.0024 s^2 + 0.11 s + 1
 
Continuous-time transfer function.