Question

cos 70 ÷ sin 20 + cos 55 cosec 35 ÷ tan 5 × tan 25× tan 45 × tan 65 × tan 85​

Answer 1

Step-by-step explanation:

cos70/sin 20∘+ cosec55cos5/tan5∘tan25∘tan45∘tan65∘tan85∘

=scos(90∘−20∘)/ sin 20 +cos55∘cosec(90∘−55∘)/tan5∘tan25∘tan45∘tan(90∘−25∘)tan(90∘−5∘)

=sin20/sin20∘+cos55∘sec55/tan5∘tan25∘tan45∘cot25∘cot5∘∘

=1+tan45∘1=1+1=2

[∵tan5∘cot5∘=1andtan25∘cot25∘=1,sec55∘cos55∘=1]