\(tanα + cotα = 2\) হলে, \(tan^{13} α + cot^{13} α \) -এর মান (a) 1 (b) 0 (c) 2 (d) কোনোটিই নয়

Answer: C
\(tan\alpha+cot\alpha=2\)
বা, \(tan\alpha+\cfrac{1}{tan\alpha}=2\)
বা, \(\cfrac{tan^2\alpha+1}{tan\alpha}=2\)
বা, \(tan^2\alpha+1=2tan\alpha\)
বা, \(tan^2\alpha+1-2tan\alpha=0\)
বা, \((tan\alpha-1)^2=0\)
বা, \(tan\alpha-1=0\)
বা, \(tan\alpha=1\)
\(\therefore cot\alpha=1\)

\(\therefore tan^{13}α+cot^{13}α =1^{13}+1^{13}=1+1=2\)

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