Answer-tan 4˚ × tan 43˚ × tan 47˚ × tan 86˚ = ?

We know that If tanA tanB 1 then A B are complementary angles it means A B 90 Here 4 86 90 43 47 90 So tan 4 tan 86 1 tan 43 tan 47 1 Hence tan 4 tan 43 tan 47 tan 86 1