Problem:
Find the norm and argument (phase angle in radians) of $\frac{3+15 i}{\sqrt{\pi }}$.
Answer:
Norm: $3 \sqrt{\frac{26}{\pi }}$
Argument: $\tan ^{-1}(5)$
{'source': 'AMPS', 'file': 'amps/mathematica/algebra/complex_norm_and_arg/6464.txt'}