Inputting a function from Userform and performing that in VBA

[Shreshth]

Hi so I want to create an application where a user can input up to 4 functions and those functions are put in like x^2, sqrt(x) and so on. Now once I input it, i want to perform the inputted function on a vector, so ln(x) is entered, then the ln of an array should be returned, how do I make it?

 

[Kaper]

If it is just one of 4 functions let user select a function from some list like listbox/dropdown/optionbuttons,... and then perform operations using: Select Case construction.
If a text of exuation is to be inputted, Application.Evaluate method could be the solution for you. See: Application.Evaluate method (Excel)