Question

evaluate: tan5 tan25 tan30 tan65 tan85

Answer 1

tan5*tan25*tan30*tan(90-25)8tan(90-5)
on simplyfyng we have tan 30 left
ans is 1/√3

Answer 2

5 + 85 = 90 25 + 65 = 90 tan(5) tan(25) tan(30) tan(65) tan(85) = tan(5)tan(85) × tan(25)tan(65) × tan(30) = 1 × 1 × tan(30) = tan(30) = 1/√3