### Printing _sage_var_x instead of x

Following the section "symbolic maths" in the quickstar of sagemath's web page
I put

sage: f=1-sin(x)^2

If I write Print(f) it works fine, but when I do the "pretty printing" :

sage: print(maxima(f))

I get

1-sinĀ²(_SAGE_VAR_x)

instead of $$1-sinĀ²(x)$$

which the quickstart says I should get. Why I am printing "_sage_var_x" and how can I replace it by just $x$?