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[tan20°/cosec70°]*(tan20°/cosec70°)+(cot20°/sec70°)*(cot20°/sec70°)+2tan15°tan45°tan75° |
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Answer» (tan20/cosec70)2+(cot20/sec70)^2+2tan15tan45tan75={tan(90-20)/cosec70}^2+{cot90-20)/sec70}^2+2(tan90-15)tan45 tan 75=(cot70/cosec70)^2 + (tan70/sec70) ^2+ 2(cot75 tan 45 tan75 )=(cos 70/sin70/1/sin70)^2 +(sin70/cos70/1/cos70) ^2+2(1×1)=(cos70+sin70)^2 +2=1+2=3... |
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