In Maple 15.01, the commands
f := x -> sin(2 x)
h := n -> (1/Pi) int(f(x) sin(n x), x = -Pi .. Pi)
g := x -> add(h(n) sin(n x), n = 1 .. 4)
which is what I expect. However, the command
results in the error message
"Error, unable to evaluate function `int` in evalhf"
so evalhf is not being passed sin(4) as I want.
How can I force the addition to be evaluated so that g(x)
actually is sin(2 x), which evalhf can then deal with?
(Note that this *could* be done by running the command
add(h(n) sin(n x), n = 1 .. 4)
and then copy-and-pasting the output into the definition of g, but I'm looking for a less ugly solution.)