Problem with a function tf

Hello everyone, yesterday i was using Matlab 2020a creating a proyect using de function 'tf' but Matlab doesn't recognize this comand to do a transfer function, i used the correct syntax, I update to Matlab 2020b because i learned that it could be the versión that i used, but i have the same problem, apparently i have already install CONTROL SYSTEM TOOLBOX but it doesn't works

[Fangjun Jiang]

run "sys = tf([1 2],[1 0 10])" and what is the error?

[Victor Alfonso Andrade Soto]

Unrecognize the comand "tf"

[Fangjun Jiang]

run "ver control" to verify you have the toolbox

[Victor Alfonso Andrade Soto]

Undefined function 'tf' for input arguments of type 'double'.

[Walter Roberson]

You do not appear to have Control System Toolbox installed.

[Victor Alfonso Andrade Soto]

When i tried to install that complement i saw that there is a message and said that the complements is already install in my computer.

Answer 1

[Star Strider]

Run these from a script or your Command Window:

restoredefaultpath 
rehash toolboxcache 

and try using tf again.

If it still is not working after that, Contact Support

[Victor Alfonso Andrade Soto]

I doesn't work yet

[Star Strider]

Apparently you never managed to install the Control System Toolbox, although in your original Question, you said that you had installed it.

Contact Support at the link I provided. They will help you figure out how to get it installed and working correctly.