def X_n(n, a, x):
 (n, a, x) = map(S, [n, a, x])
 C = sqrt((2 / a))
 return (C * sin((((pi * n) * x) / a)))

def X_n ( n , a , x ) : ( n , a , x ) = map ( S , [ n , a , x ] ) C = sqrt ( ( 2 / a ) ) return ( C * sin ( ( ( ( pi * n ) * x ) / a ) ) )
returns the wavefunction x_{n} for an infinite 1d box n the "principal" quantum number .