2.6: Modulus sketch and composite inverse

0606/22/M/J/18 — Question 10 · 7 marks

(a)(i)
On the axes below, sketch the graph of y=(x+3)(x5)y = |(x + 3)(x - 5)| showing the coordinates of the points where the curve meets the xx-axis.
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(a)(ii)
Write down a suitable domain for the function f(x)=(x+3)(x5)f(x) = |(x + 3)(x - 5)| such that ff has an inverse.
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(b)(i)
The functions gg and hh are defined by g(x)=3x1g(x) = 3x - 1 for x>1x > 1 and h(x)=4xh(x) = \dfrac{4}{x} for x0x \neq 0.
Find hg(x)hg(x).
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(b)(ii)
Find (hg)1(x)(hg)^{-1}(x).
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(c)
Given that p(a)=bp(a) = b and that the function pp has an inverse, write down p1(b)p^{-1}(b).
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