1.9: Product-rule differentiation and equation of a normal

0606/11/M/J/19 — Question 11 · 9 marks

It is given that y=(x2+1)(2x3)12y = (x^{2} + 1)(2x - 3)^{\frac{1}{2}}.
(i)
Show that dydx=Px2+Qx+1(2x3)12\dfrac{\mathrm{d}y}{\mathrm{d}x} = \dfrac{Px^{2} + Qx + 1}{(2x - 3)^{\frac{1}{2}}}, where PP and QQ are integers.
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(ii)
Hence find the equation of the normal to the curve y=(x2+1)(2x3)12y = (x^{2} + 1)(2x - 3)^{\frac{1}{2}} at the point where x=2x = 2, giving your answer in the form ax+by+c=0ax + by + c = 0, where aa, bb and cc are integers.
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