Question

^3 cot 20 cot 40 cot 80 = 1
​

Answer 1

Answer:

Step-by-step explanation:

3 cot20 cot40 cot80

=3 cot20 cot(60-20) cot(60+20)

=3 cot20 cot20+root3/1-root3cot20  cot20+root3/1+root3cot20

=3 cot20 cot^220-3/1-3cot^220

=3 cot^60

=3*1/3

=1