How to do quick calculations for single-variable expression for complex-valued input?

[Wes Loewer]

The quickest way to evaluate an expression at a value is to use the vertical bar "where" function, i.e. where x = some value.

x^2+1|x = 2*i

The vertical bar is found on the top row of the templates. On the virtual calculator, just use the vertical bar (pipe) key.

Is this what you had in mind?