Some of my answers include "і" signs, what should I do to get a regular answer? At first, I thought it was a problem in the cosine equations but later saw the same problem in other formulas. TROPtaKhV_Lb2.sm(356 KiB) downloaded 23 time(s).
"i" indicates that this is a complex number with an imaginary part. It is completely normal for the cases you have exposed since the square root of a negative number does not make sense in the real field (it is a complex number); in the same way, the arc-cosine makes sense in the real field only for numbers less than or equal to 1