0606 P23 - Nov 2025 - Q2 - 10 marks
(a) (i)
The diagram shows the graph of \(y=\mathrm{f}(x)\).
On the same diagram sketch the graph of \(y=\mathrm{f}^{-1}(x)\).
(ii) Describe the relationship between the graph of \(\mathrm{f}(x)\) and the graph of \(\mathrm{f}^{-1}(x)\).
(b) A function g is defined by \(\mathrm{g}(x)=\mathrm{e}^{\sqrt{x-2}}\) for \(x \geqslant 2\).
(i) Find an expression for \(\mathrm{g}^{-1}(x)\).
(ii) Write down the range of \(\mathrm{g}^{-1}\).
(iii) A function h is defined by \(\mathrm{h}(x)=\frac{1}{x^{2}}+2\) for \(x\gt 0\).
Find an expression for \(\operatorname{gh}(x)\) in its simplest form.
0606 P12 - Jun 2025 - Q9 - 8 marks
It is given that \(\mathrm{f}(x)=2\ln(3x-4)\), for \(x\gt a\), and that \(\mathrm{f}^{-1}\) exists.
(a) Find the least possible value of \(a\).
(b) For your value of \(a\), find the range of \(\mathrm{f}\).
(c) For your value of \(a\), find an expression for \(\mathrm{f}^{-1}(x)\).
(d) It is given that the equation \(\mathrm{f}(x)=\mathrm{f}^{-1}(x)\) has two roots. For your value of \(a\), sketch the graphs of \(y=\mathrm{f}(x)\) and \(y=\mathrm{f}^{-1}(x)\) on the axes. Label each graph. State the intercepts of each graph with the axes. State the equations of any asymptotes.
0606 P13 - Jun 2025 - Q9 - 12 marks
The function f is defined by \(\mathrm{f}(x)=-2 x^{2}+9 x-10\) for \(0 \leqslant x \leqslant 3\). (a) (i) Write \(\mathrm{f}(x)\) in the form \(a+b(x+c)^{2}\) where \(a, b\) and \(c\) are constants.
(ii) Hence determine whether or not \(\mathrm{f}^{-1}\) exists.
(b) The function g is defined by \(\mathrm{g}(x)=3 \ln (5-2 x)\) for \(0 \leqslant x\lt 2.5\). (i) 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.
(ii) Find an expression for \(\mathrm{g}^{-1}(x)\).
(iii) Find the domain and range of \(\mathrm{g}^{-1}\).
Give each of your answers in exact form.
0606 P21 - Jun 2025 - Q7 - 8 marks
(a) The function f is defined by \(\mathrm{f}(x)=2 \mathrm{e}^{-x}+3\) for \(x \in \mathbb{R}\). On the axes, sketch the graph of \(y=\mathrm{f}(x)\) and hence, on the same axes, sketch the graph of \(y=\mathrm{f}^{-1}(x)\). Show clearly - the positions of any points where your graphs meet the coordinate axes - the positions of any asymptotes.
(b) The function g is defined by \(\mathrm{g}(x)=2-\frac{3}{\mathrm{e}^{x}+2}\) for \(x \geqslant 0\).
Given that \(\mathrm{g}^{-1}\) exists, find an expression for \(\mathrm{g}^{-1}(x)\) and state its domain.
0606 P12 - Mar 2025 - Q5 - 8 marks
(a) Write \(2x^2-2x+3\) in the form \(a(x+b)^2+c\), where \(a\), \(b\) and \(c\) are constants.
It is given that \(\mathrm{f}(x)=2x^2-2x+3\), for \(x\leqslant p\).
(b) Write down the greatest value of \(p\) for which \(\mathrm{f}\) has an inverse.
(c) Using this value of \(p\), write down the range of \(\mathrm{f}\).
(d) Using this value of \(p\), find an expression for \(\mathrm{f}^{-1}\).
0606 P21 - Nov 2024 - Q11 - 7 marks
(a) \(\mathrm{f}(x)=\frac{x}{x-1}\) for \(-10 \leqslant x \leqslant 10, x \neq 1\). The diagram shows the graph of \(y=\mathrm{f}(x)\). (i) Use the diagram to explain why f is a function.
(ii) Find \(\mathrm{ff}(x)\), giving your answer in its simplest form.
(iii) Using your answer to part (ii) state the relationship between the functions f and \(\mathrm{f}^{-1}\).
(iv) Explain how the diagram shows the relationship between f and \(\mathrm{f}^{-1}\).
(b) A function g is defined by \(\mathrm{g}(x)=\frac{x}{x-1}\) for \(x \geqslant 2\). Find the range of g .
(c) A function h is defined by \(\mathrm{h}(x)=\frac{2 x}{3 x+1}\) for the largest possible domain. State the domain of h .
0606 P23 - Nov 2024 - Q2 - 9 marks
The function f is defined by \(\mathrm{f}(x)=1-4 x-x^{2}\) for all real values of \(x\). (a) Write \(\mathrm{f}(x)\) in the form \(a-(x+b)^{2}\), where \(a\) and \(b\) are constants.
(b) Find the range of f.
The function g is defined by \(\mathrm{g}(x)=1-4 x-x^{2}\) for \(x \geqslant k\), where \(k\) is a constant. (c) State the least possible value of \(k\) such that g has an inverse.
(d) Using your value of \(k\), find \(\mathrm{g}^{-1}(x)\), stating its domain and range.
0606 P21 - Jun 2024 - Q9 - 7 marks
The functions \(f\) and \(g\) are defined by \(\begin{array}{ll} \mathrm{f}(x)=\frac{3 x^{2}}{4 x-1} & \text { for } x\lt 0 \\ \mathrm{~g}(x)=\frac{1}{x^{2}} & \text { for } x\lt 0 \end{array}\) (a) Explain why the function fg does not exist. (b) Given that the function gf does exist, find and simplify an expression for \(\mathrm{gf}(x)\). (c) Show that \(\mathrm{f}^{-1}(x)\) can be written as \(\frac{p x-\sqrt{x(q x+r)}}{3}\) where \(p, q\) and \(r\) are integers.
0606 P22 - Jun 2024 - Q10 - 8 marks
The functions \(f\) and \(f g\) are defined by \(\begin{array}{ll} \mathrm{f}(x)=\mathrm{e}^{x^{2}+3} & \text { for } x\lt 0 \\ \mathrm{fg}(x)=\mathrm{e}^{2 x} & \text { for } x\gt \frac{3}{2} \end{array}\) (a) Explain why \(\mathrm{f}^{-1}\) exists. (b) Find an expression for \(\mathrm{f}^{-1}(x)\) and state the domain and range of \(\mathrm{f}^{-1}\). (c) Hence find and simplify an expression for \(\mathrm{g}(x)\).
0606 P21 - Nov 2023 - Q9 - 7 marks
The functions \(\mathrm f\) and \(\mathrm g\) are defined as follows, for all real values of \(x\).
\(\mathrm f(x)=2x^2-1\)
\(\mathrm g(x)=\mathrm e^x+1\)
(a) Solve the equation \(\mathrm{fg}(x)=8\).
(b) For each of the functions \(\mathrm f\) and \(\mathrm g\), either explain why the inverse function does not exist or find the inverse function, stating its domain.
0606 P22 - Mar 2021 - Q10 - 8 marks
The function \(f\) is defined by
\(f(x)=\frac{\sqrt{4x^2-1}}{2x}\quad\text{for }0.5\leqslant x\leqslant1.5.\)
The diagram shows a sketch of \(y=f(x)\).
(a)
(i) It is given that \(f^{-1}\) exists. Find the domain and range of \(f^{-1}\).
(ii) Find an expression for \(f^{-1}(x)\).
(b) The function \(g\) is defined by \(g(x)=e^{x^2}\) for all real \(x\). Show that \(gf(x)=e^{\left(1-\frac{a}{bx^2}\right)}\), where \(a\) and \(b\) are integers.
0606 P22 - Jun 2021 - Q13 - 7 marks
The functions \(\mathrm f\) and \(\mathrm g\) are defined, for \(x\gt 0\), by
\(\mathrm f(x)=\frac{2x^2-1}{3x}, \qquad \mathrm g(x)=\frac1x.\)
(a) Find and simplify an expression for \(\mathrm{fg}(x)\).
(b)
(i) Given that \(\mathrm f^{-1}\) exists, write down the range of \(\mathrm f^{-1}\).
(ii) Show that
\(\mathrm f^{-1}(x)=\frac{px+\sqrt{qx^2+r}}{4},\)
where \(p\), \(q\) and \(r\) are integers.
0606 P23 - Jun 2021 - Q9 - 10 marks
(a) The function \(\mathrm f\) is defined, for all real \(x\), by
\(\mathrm f(x)=13-4x-2x^2.\)
(i) Write \(\mathrm f(x)\) in the form \(a+b(x+c)^2\), where \(a\), \(b\) and \(c\) are constants.
(ii) Hence write down the range of \(\mathrm f\).
(b) The function \(\mathrm g\) is defined, for \(x\geq1\), by
\(\mathrm g(x)=\sqrt{x^2+2x-1}.\)
(i) Given that \(\mathrm g^{-1}(x)\) exists, write down the domain and range of \(\mathrm g^{-1}\).
(ii) Show that
\(\mathrm g^{-1}(x)=-1+\sqrt{px^2+q},\)
where \(p\) and \(q\) are integers.
0606 P22 - Mar 2020 - Q10 - 9 marks
(a) The function \(g\) is defined by
\(g(x)=3+\frac1x,\qquad x\geq1.\)
Find an expression for \(g^{-1}(x)\), and state the domain and range of \(g^{-1}\).
(b) The function \(h\) is defined by
\(h(x)=2\ln(3x-1),\qquad x\gt \frac23.\)
The graph of \(y=h(x)\) intersects the line \(y=x\) at two distinct points. On the same axes, sketch the graphs of \(y=h(x)\) and \(y=h^{-1}(x)\).
0606 P12 - Jun 2020 - Q5 - 9 marks
The function \(f\) is defined by
\(f:x\mapsto(2x+3)^2,\qquad x\gt0.\)
(a) State the range of \(f\).
(b) Explain why \(f\) has an inverse.
(c) Find \(f^{-1}\).
(d) State the domain of \(f^{-1}\).
(e) Given that
\(g:x\mapsto\ln(x+4),\qquad x\gt0,\)
find the exact solution of \(fg(x)=49\).
0606 P22 - Mar 2019 - Q9 - 13 marks
(a) It is given that \(g(x)=6x^4+5\) for all real \(x\).
(i) Explain why \(g\) is a function but does not have an inverse.
(ii) Find \(g^2(x)\) and state its domain.
It is given that \(h(x)=6x^4+5\) for \(x\leq k\).
(iii) State the greatest value of \(k\) such that \(h^{-1}\) exists.
(iv) For this value of \(k\), find \(h^{-1}(x)\).
(b) The function \(p\) is defined by \(p(x)=3e^x+2\) for all real \(x\).
(i) State the range of \(p\).
(ii) Sketch and label the graphs of \(y=p(x)\) and \(y=p^{-1}(x)\). State the coordinates of any points of intersection with the coordinate axes.
(iii) Hence explain why the equation \(p(x)=p^{-1}(x)\) has no solutions.
0606 P13 - Jun 2019 - Q8 - 10 marks
\(f:x\mapsto e^{3x}\) for \(x\in\mathbb R\), and \(g:x\mapsto2x^2+1\) for \(x\geq0\).
(i) Write down the range of \(g\).
(ii) Show that \(f^{-1}g(\sqrt{62})=\ln5\).
(iii) Solve \(f'(x)=6g''(x)\), giving your answer in the form \(\ln a\), where \(a\) is an integer.
(iv) Sketch the graph of \(y=g\) and the graph of \(y=g^{-1}\), showing the points where the graphs meet the coordinate axes.
0606 P22 - Jun 2019 - Q12 - 10 marks
The functions \(f\) and \(g\) are defined by \(f(x)=5x-2\) for \(x\gt 1\), and \(g(x)=4x^2-9\) for \(x\gt 0\).
(a) (i) State the range of \(g\).
(ii) Find the domain of \(gf\).
(iii) Showing all your working, find the exact solutions of \(gf(x)=45\).
(b) The function \(h\) is defined by \(h(x)=\sqrt{x^2-1}\) for \(x\leq-1\).
(i) State the geometrical relationship between the graphs of \(y=h(x)\) and \(y=h^{-1}(x)\).
(ii) Find an expression for \(h^{-1}(x)\).
0606 P22 - Mar 2018 - Q10 - 10 marks
(a) The function \(f\) is defined by \(f(x)=\sqrt{1+x^2}\), for all real values of \(x\). The graph of \(y=f(x)\) is given.
(i) Explain, with reference to the graph, why \(f\) does not have an inverse.
(ii) Find \(f^2(x)\).
(b) The function \(g\) is defined, for \(x\gt k\), by \(g(x)=\sqrt{1+x^2}\), and \(g\) has an inverse.
(i) Write down a possible value for \(k\).
(ii) Find \(g^{-1}(x)\).
(c) The function \(h\) is defined, for all real values of \(x\), by \(h(x)=4e^x+2\). Sketch the graph of \(y=h(x)\). Hence, on the same axes, sketch the graph of \(y=h^{-1}(x)\). Give the coordinates of any points where your graphs meet the coordinate axes.
0606 P21 - Jun 2018 - Q5 - 6 marks
The function \(\mathrm f\) is defined by
\(\mathrm f(x)=\frac1{2x-5},\qquad x\gt2.5.\)
(i) Find an expression for \(\mathrm f^{-1}(x)\).
(ii) State the domain of \(\mathrm f^{-1}(x)\).
(iii) Find an expression for \(\mathrm f^2(x)\), giving your answer in the form \(\dfrac{ax+b}{cx+d}\), where \(a\), \(b\), \(c\) and \(d\) are integers to be found.
0606 P23 - Jun 2018 - Q5 - 6 marks
The function \(\mathrm f\) is defined by
\(\mathrm f(x)=\frac1{2x-5},\qquad x\gt2.5.\)
(i) Find an expression for \(\mathrm f^{-1}(x)\).
(ii) State the domain of \(\mathrm f^{-1}(x)\).
(iii) Find an expression for \(\mathrm f^2(x)\), giving your answer in the form \(\dfrac{ax+b}{cx+d}\), where \(a\), \(b\), \(c\) and \(d\) are integers to be found.
0606 P11 - Nov 2018 - Q11 - 9 marks
(a) \(f(x)=3-\cos2x\), for \(0\leq x\leq\dfrac{\pi}{2}\).
(i) Write down the range of \(f\).
(ii) Find the exact value of \(f^{-1}(2.5)\).
(b) \(g(x)=3-x^2\), for \(x\in\mathbb R\). Find the exact solutions of \(g^2(x)=-6\).
0606 P13 - Nov 2018 - Q8 - 9 marks
\(f(x)=5+\sin\frac{x}{4} \quad\text{for}\quad 0\leq x\leq2\pi\text{ radians}\)
\(g(x)=x-\frac{\pi}{3} \quad\text{for}\quad x\in\mathbb R\)
(i) Write down the range of \(f(x)\).
(ii) Find \(f^{-1}(x)\) and write down its range.
(iii) Solve \(2fg(x)=11\).
0606 P11 - Jun 2017 - Q4 - 8 marks
(a) It is given that \(f(x)=3e^{-4x}+5\), for \(x\in\mathbb R\).
(i) State the range of \(f\).
(ii) Find \(f^{-1}\) and state its domain.
(b) It is given that \(g(x)=x^2+5\) and \(h(x)=\ln x\), for \(x\gt 0\). Solve \(hg(x)=2\).
0606 P11 - Nov 2017 - Q6 - 11 marks
(a) Functions \(f\) and \(g\) are such that, for \(x\in\mathbb R\), \(f(x)=x^2+3\) and \(g(x)=4x-1\).
(i) State the range of \(f\).
(ii) Solve \(fg(x)=4\).
(b) A function \(h\) is such that \(h(x)=\dfrac{2x+1}{x-4}\), for \(x\in\mathbb R\), \(x\neq4\).
(i) Find \(h^{-1}(x)\) and state its range.
(ii) Find \(h^2(x)\), giving your answer in its simplest form.
0606 P12 - Nov 2017 - Q6 - 7 marks
Functions \(f\) and \(g\) are defined, for \(x\gt 0\), by \(f(x)=\ln x\) and \(g(x)=2x^2+3\).
(i) Write down the range of \(f\).
(ii) Write down the range of \(g\).
(iii) Find the exact value of \(f^{-1}g(4)\).
(iv) Find \(g^{-1}(x)\) and state its domain.
0606 P23 - Nov 2017 - Q6 - 9 marks
The functions \(f\) and \(g\) are defined by
\(f(x)=(x+2)^2+1,\)
\(g(x)=\dfrac{x-2}{2x-1}\), where \(x\ne\dfrac12\).
(i) Find \(f^2(-3)\).
(ii) Show that \(g^{-1}(x)=g(x)\).
(iii) Solve \(gf(x)=\dfrac8{19}\).