Question

cot 12 cot 38 cot 52 cot 60 cot 78

Answer 1

cot(90-78)cot(90-52)cot52.1byroot3.cot78
tan78.tan52.cot52.1by root3.cot78
tan78.tan52.1\tan52.1by root 3.1\tan78
answer is 1by root 3