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Heya Users___________❤❤Question is in attachmentSolve plZzTysm☺ |
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Answer» Now, ∫ (COTX + x) cot²x dx = ∫ (cotx + x) (cosec²x - 1) dx [∵cosec²x - cot²x = 1] = ∫ cotx cosec²x dx - ∫ cotx dx + ∫ x cosec²x dx - ∫ x dx ...(1) ______ ∴ ∫ cotx cosec²x dx = ∫ cotx d (- cotx) = - (cot²x)/2 Here, ∫ cotx dx = log (SINX) ∴ ∫ x cosec²x dx = x ∫ cosec²x dx - ∫ {d/dx (x) × ∫ cosec²x dx} dx = x (- cotx) - ∫ (- cotx) dx [∵ d/dx (x) = 1 ] = - x cotx + ∫ cotx dx = - x cotx + log (sinx) ∴ ∫ x dx = (x²)/2 From (i), we GET the required integral as ∫ (cotx + x) cot²x dx = - (cot²x)/2 - log (sinx) - x cotx + log (sinx) - (x²)/2 + c, where c is integral constant = - (cot²x)/2 - x cotx - (x²)/2 + c # |
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