"All limits, especially national ones, are contrary to the nature of mathematics… Mathematics knows no races… For mathematics the whole cultural world is a single country" – David Hilbert, the foremost mathematician of the 20th century, speaking as the Nazis neared power in his native Germany.

You can write these answers in different ways, which are all correct. For example, 2 √2 (cos π/4 + i sin π/4) can also be written as 2 √2 cis π/4 or as 2 √2 ∠ π/4. All three ways are correct.