http://forwhoallvglhpsx6dhycfb4fu4a2lqkvxtwlivruw765qxofyns7wqd.onion/i.php
If you click Show/Hide, it can do trigonometry, Pythagoras and (finally!) Euler / rectangular / polar conversions. After swapping rows, click use result. (See below for what input went into the calculator) , i , i