sec 17∘cosec 73∘+tan 68∘cot 22∘−[cos2 44∘+cos2 46∘]=___.
1
sec 17∘cosec 73∘+tan 68∘cot 22∘−[cos2 44∘+cos2 46∘]
=sec 17∘cosec (90∘−17∘)+tan 68∘cot (90∘−68∘)−[cos2 44∘+cos2 (90∘−44∘)]
=sec 17∘sec 17∘+tan 68∘tan 68∘−[cos2 44∘+sin2 44∘]....(complementary angles)
=1+1−1
=1