given -2+4i, express the complex number in polar form. I know the answer is 2 root 5(cos2.03 + isin2.03), but I don't know where the 2.03 comes from. Can someone explain please?

Two groups of students were asked how many hours they spent reading each day. the table below shows the numbers for each group: group a 1 2 1 1 3 3 2 2 3 group b 3 2 3 2 2 2 1 1 2 based on the table, which of the following is true? the interquartile range for group a students is 0.5 less than the interquartile range for group b students. the interquartile range for group a students is equal to the interquartile range for group b students. the interquartile range for group a employees is 0.5 more than to the interquartile range for group b students. the interquartile range for group a employees is 1 more than the interquartile range for group b students.