3.76: Partial fractions integration

0606/12/O/N/22 — Question 9 · 9 marks

(a)
Show that 12x+11(2x+1)2+44x1=24x2+14x+4(2x+1)2(4x1)\dfrac{1}{2x + 1} - \dfrac{1}{(2x + 1)^{2}} + \dfrac{4}{4x - 1} = \dfrac{24x^{2} + 14x + 4}{(2x + 1)^{2}(4x - 1)}.
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(b)
Hence find 12124x2+14x+4(2x+1)2(4x1)dx\displaystyle\int_{\frac{1}{2}}^{1}\dfrac{24x^{2} + 14x + 4}{(2x + 1)^{2}(4x - 1)}\,\mathrm{d}x, giving your answer in the form 12lnp+q\dfrac{1}{2}\mathrm{ln}\,p + q, where pp and qq are rational numbers.
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