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Find the sum of n terms of the series (4-1/n)+(4-2/n)+.... |
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Answer» (4-1/n)+(4-2/n)+.......=4n-1/n(1+2+3........n){tex}\\begin{array}{l}\\text{=4n-}\\frac1{\\mathrm n}\\times\\frac{\\mathrm n(\\mathrm n+1)}2\\\\\\text{=4n-}\\frac{n+1}2\\\\\\text{=}\\frac{8n-n-1}2\\\\\\text{=}\\frac{7n-1}2\\end{array}{/tex} Sn = (7n-1)/2 |
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