2025 IGCSE Additional Mathematics May/June 0606/13 Q9

2025 IGCSE Additional Mathematics May/June 0606/13 Q9

12 marks

The function \(\mathrm f\) is defined by \(\mathrm f(x)=-2x^2+9x-10\) for \(0\le x\le3\).

    1. Write \(\mathrm f(x)\) in the form \(a+b(x+c)^2\) where \(a\), \(b\) and \(c\) are constants.[3]
    2. Hence determine whether or not \(\mathrm f^{-1}\) exists.[2]
  1. The function \(\mathrm g\) is defined by \(\mathrm g(x)=3\ln(5-2x)\) for \(0\le x<2.5\).
    1. On the axes, sketch the graph of \(y=\mathrm g(x)\).
      State the exact values of the intercepts with the coordinate axes and the equation of any asymptote.[3]
    2. Find an expression for \(\mathrm g^{-1}(x)\).[2]
    3. Find the domain and range of \(\mathrm g^{-1}\).
      Give each of your answers in exact form.[2]

Solution:

Solution locked

Sign in to view the step-by-step solution

Similar questions are unavailable for this question.
Answer:(a)(i) \(\dfrac18-2\left(x-\dfrac94\right)^2\) (ii) No inverse on the given domain. (b)(i) Intercepts \((0,3\ln5)\), \((2,0)\); asymptote \(x=\dfrac52\). (ii) \(\dfrac{5-\mathrm e^{x/3}}2\) (iii) Domain \(x\le3\ln5\); range \(0\le\mathrm g^{-1}(x)<\dfrac52\).

Need help? Join our JC Math tuition classes.

Learn more