HP15C HP42S integration of trig differs in *rad and *deg

[hansepie]

f(x) = sin(x)

When performing integration in RAD=mode lower limit 0 and upper limit PI/2 it returns 1.0000.

When performing integration in DEG-mode lower limit 0 and upper limit 90 it returns 57.2960.

I expected the same results.

HP-42S and HP-15C give the same results.

What do I miss?

Thank's.

Hans