[Maxima] plotting (sin (x))^2 +(cos(x))^2)

[Doug Edmunds (gmail)]

Using wxMaxima 0.8.3 / Maxima 5.19.2

wxplot2d([(sin (x))^2,(cos(x))^2], [x,-5,5])$
looks correct.

wxplot2d([(sin (x))^2 +(cos(x))^2], [x,-5,5])$
should produce a straight line (y=1),
but doesn't.  What do I need to do?

- dae