2 tan 70∘cot 20∘−tan 33∘cot 57∘−√2 cos 45∘= _____
0
2
1
-1
2 tan 70∘cot 20∘−tan 33∘cot 57∘−√2 cos 45∘
=2 tan (90−20∘)cot 20−tan (90−57∘)cot 57∘−√2(1√2) =2 cot 20∘cot 20∘−cot 57∘cot 57∘−1(∵ tan(90−θ)=cot θ) = 2 - 1 - 1 = 0
The value of tan58∘ tan32∘ tan57∘ tan33∘ is