# Function (IB SL)

$\def\frac{\dfrac}$ $\def\iixi#1#2{\left(\begin{array}{c}#1\\#2\end{array}\right)}\let\frac=\dfrac$
1 (IB/s1/2018/November/Paper2/q3)
[Maximum mark: 7]
Let $f(x)=\frac{6 x-1}{2 x+3}$, for $x \neq-\frac{3}{2}$
 (a) For the graph of $f$.

(i) find the $y$-intercept;
(ii) find the equation of the vertical asymptote;
(iii) find the equation of the horizontal asymptote.
 (b) Hence or otherwise, write down $\displaystyle\lim _{x \rightarrow \infty}\left(\frac{6 x-1}{2 x+3}\right)$.

2 (IB/s1/2018/May/paper2tz2/q7)
[Maximum mark: 7 ]
Let $f(x)=\frac{8 x-5}{c x+6}$ for $x \neq-\frac{6}{c}, c \neq 0$
 (a) The line $x=3$ is a vertical asymptote to the graph of $f$. Find the value of $c .$
 (b) Write down the equation of the horizontal asymptote to the graph of $f$.
 (c ) The line $y=k$, where $k \in \mathbb{R}$ intersects the graph of $|f(x)|$ at exactly one point. Find the possible values of $k$.

3 (IB/s1/2017/May/paper2tz1/q3)
[Maximum mark: 6]
Consider the graph of $f(x)=\frac{\mathrm{e}^{x}}{5 x-10}+3$, for $x \neq 2$.
 (a) Find the $y$-intercept.
 (b) Find the equation of the vertical asymptote.
 (c ) Find the minimum value of $f(x)$ for $x>2$.
[2]

4 (IB/sl/2016/May/paper2tz2/q3)
[Maximum mark: 7]
Let $f(x)=e^{a, r}-2$.
 (a) For the graph of $f$ (i) write down the $y$-intercept: (ii) find the $x$-intercept: (iii) write down the equation of the horizontal asymptote.
 (b) On the following grid, sketch the graph of $f$, for $-4 \leq x \leq 4$. [3]

5 (IB/s1/2016/May/paper2tz2/q9)
[Maximum mark: 14]
Let $f(x)=\frac{1}{x-1}+2$, for $x>1 .$
 (a) Write down the equation of the horizontal asymptote of the graph of $f$.
 (b) Find $f^{\prime}(x)$. [2]

Let $g(x)=a \mathrm{e}^{-x}+b$, for $x \geq 1$. The graphs of $f$ and $g$ have the same horizontal asymptote.
 (c) Write down the value of $b$.
 (d) Given that $g^{\prime}(1)=-c$, find the value of $a$.
 (e) There is a value of $x$, for $1 < x < 4$, for which the graphs of $f$ and $g$ have the same gradient. Find this gradient.

6 (IB/s1/2018/May/paper1tz1/q3)
[Maximum mark: 7]
Consider a function $f(x)$, for $-2 \leq x \leq 2$. The following diagram shows the graph of $f$.

 (a) Write down the value of (i) $f(0):$ (ii) $f^{-1}(1)$.
 (b) Write down the range of $f^{-1}$.
 (c) On the grid above, sketch the graph of $f^{-1}$.

7 (IB/s1/2019/November/Paper2/q3)
[Maximum mark: 7]
Let $f(x)=x-8, g(x)=x^{4}-3$ and $h(x)=f(g(x))$
 (a) Find $h(x)$.

Let $\mathrm{C}$ be a point on the graph of $h$. The tangent to the graph of $h$ at $\mathrm{C}$ is parallel to the graph of $f$.
 (b) Find the $x$-coordinate of $\mathrm{C}$.

8 (IB/s1/2019/May/paper1tz1/q4)
[Maximum mark: 6]
Let $f(x)=\frac{2 x-1}{x+3}, x \neq-3$.
 (a) Write down the equation of the vertical asymptote of the graph of $f$. [1]
 (b) Find $f^{-1}(x)$. $[3]$
 (c) Find the equation of the horizontal asymptote of the graph of $f^{-1}$. [2]

9 (IB/s1/2019/May/paper1tz2/q3)
[Maximum mark: 6]
Consider the function $f(x)=\frac{3 x+1}{x-2}, x \neq 2$.
 (a) For the graph of $f$. (i) write down the equation of the vertical asymptote; (ii) find the equation of the horizontal asymptote.

Let $g(x)=x^{2}+4, x \in \mathbb{R}$,
 (b) Find $(f \circ g)(1)$

10 (IB/s1/2019/May/paper2tz1/q8)
[Maximum mark: 13]
Let $f(x)=2 \sin (3 x)+4$ for $x \in \mathbb{R}$.
 (a) The range of $f$ is $k \leq f(x) \leq m .$ Find $k$ and $m$.

Let $g(x)=5 f(2 x)$.
 (b) Find the range of $g$.

The function $g$ can be written in the form $g(x)=10 \sin (b x)+c$.
 (c) (i) Find the value of $b$ and of $c$. (ii) Find the period of $g$.
 (d) The equation $g(x)=12$ has two solutions where $\pi \leq x \leq \frac{4 \pi}{3}$. Find both solutions: [3]

11 (IB/s1/2019/May/paper2tz1/q9)
[Maximum mark: 16]
Let $f(x)=\frac{16}{x}$. The line $L$ is tangent to the graph of $f$ at $x=8$.
 (a) Find the gradient of $L$. [2]

$L$ can be expressed in the form $r=\left(\begin{array}{l}8 \\ 2\end{array}\right)+i u$.
 (b) Find $u$. [2]

The direction vector of $y=x$ is $\left(\begin{array}{l}1 \\ 1\end{array}\right)$.
 (c) Find the acute angle between $y=x$ and $L$.
 (d) (i) Find $(f \circ f)(x)$. (ii) Hence, write down $f^{-1}(x)$. (iii) Hence or otherwise, find the obtuse angle formed by the tangent line to $f$ at $x=8$ and the tangent line to $f$ at $x=2$. [7]

12 (IB/sl/2018/November/Paper1/q2)
[Maximum mark: 5]
Two functions, $f$ and $g$, are defined in the following table. $$\begin{array}{|c|r|r|r|r|}\hline x & -2 & 1 & 3 & 6 \\\hline f(x) & 6 & 3 & 1 & -2 \\\hline g(x) & -7 & -2 & 5 & 9 \\\hline\end{array}$$
 (a) Write down the value of $f(1)$.
 (b) Find the value of $(g \circ f)(1)$.
 (c) Find the value of $g^{-1}(-2)$. [2]

13 (IB/s1/2018/May/paper1tz1/q1)
[Maximum mark: 6]
Let $f(x)=\sqrt{x+2}$ for $x \geq-2$ and $g(x)=3 x-7$ for $x \in \mathbb{R}$.
 (a) Write down $f(14)$.
 (b) Find $(g \circ f)(14)$.
 (c) Find $g^{-1}(x)$.

 14 (IB/s1/2018/May/paper1tz1/q7) [Maximum mark: 7 ] Consider $f(x), g(x)$ and $h(x)$, for $x \in \mathbb{R}$ where $h(x)=(f \circ g)(x)$. Given that $g(3)=7, g^{\prime}(3)=4$ and $f^{\prime}(7)=-5$, find the gradient of the normal to the curve of $h$ at $x=3$.

15 (IB/sl/2017/November/Paper 1/q3)
[Maximum mark: 6]
The following diagram shows the graph of a function $f$, with domain $-2 \leq x \leq 4$.

The points $(-2,0)$ and $(4,7)$ lie on the graph of $f$.
 (a) Write down the range of $f$.
 (b) Write down (i) $f(2)$; (ii) $f^{-1}(2)$. [2]
 (c) On the grid opposite, sketch the graph of $f^{-1}$. $[3]$

16 (IB/s1/2017/November/Paper1/q5)
[Maximum mark: 6]
Let $f(x)=1+\mathrm{e}^{-x}$ and $g(x)=2 x+b$, for $x \in \mathbb{R}$, where $b$ is a constant.
 (a) Find $(g \circ f)(x)$. [2]
 (b) Given that $\lim _{x \rightarrow+\infty}(g \circ f)(x)=-3$, find the value of $b$. $[4]$

17 (IB/s1/2017/May/paper1tz1/q2)
[Maximum mark: 5]
Let $f(x)=5 x$ and $g(x)=x^{2}+1$, for $x \in \mathbb{R}$.
 (a) Find $f^{-1}(x)$.[2]
 (b) Find $(f \circ g)(7)$.

18 (IB/s1/2017/May/paper1tz2/q6)
[Maximum mark: 5]
The values of the functions $f$ and $g$ and their derivatives for $x=1$ and $x=8$ are shown in the following table, $$\begin{array}{|c|c|c|c|c|}\hline x & f(x) & f^{\prime}(x) & g(x) & g^{\prime}(x) \\\hline 1 & 2 & 4 & 9 & -3 \\\hline 8 & 4 & -3 & 2 & 5 \\\hline\end{array}$$
Let $h(x)=f(x) g(x)$.
 (a) Find $h(1)$.
 (b) Find $h^{\prime}(8)$. [3]

19 (IB/s1/2017/May/paper2tz2/q3)
[Maximum mark: 6]
The following diagram shows the graph of a function $y=f(x)$, for $-6 \leq x \leq-2$.
The points $(-6,6)$ and $(-2,6)$ lie on the graph of $f$. There is a minimum point at $(-4,0)$.
 (a) Write down the range of $f$.

Let $g(x)=f(x-5)$
 (b) On the grid above, sketch the graph of $g$. [2]
 (c) Write down the domain of $g$. [2]

20 (IB/s1/2016/May/paper1tz1/q1)
[Maximum mark: 5]
Let $f(x)=8 x+3$ and $g(x)=4 x$, for $x \in \mathbb{R}$
 (a) Write down $g(2)$. [1]
 (b) Find $(f \circ g)(x)$ [2]
 (c ) Find $f^{-1}(x)$. [2]

21 (IB/s1/2016/May/paper1tz2/q6)
[Maximum mark: 7]
Let $f(x)-6 x \sqrt{1-x^{2}}$, for $-1 \leq x \leq 1$, and $g(x)-\cos (x)$, for $0 \leq x \leq \pi$
Let $h(x)=(f \circ g)(x)$
 (a) Write $h(x)$ in the form $a \sin (b x)$, where $a, b \in \mathbb{Z}$.
 (b) Hence find the range of $h$. [2]

22 (IB/s1/2016/May/paper2tz1/q2)
[Maximum mark: 6]
Let $f(x)=x^{2}$ and $g(x)=3 \ln (x+1)$, for $x>-1$
 (a) Solve $f(x)=g(x)$.[3]
 (b) Find the area of the region enclosed by the graphs of $f$ and $g$. [3]

23 (IB/sl/2015/May/paper1tz1/q4)
[Maximum mark: 7]
The following diagram shows the graph of a function $f$.
 (a) Find $f^{-1}(-1)$
 (b) Find $(f \circ f)(-1)$.
 (c) On the same diagram, sketch the graph of $y=f(-x)$.

 24 (IB/sl/2015/May/paper1tz2/q6) [Maximum mark: 8] Let $f(x)=a x^{3}+b x .$ At $x=0$, the gradient of the curve of $f$ is 3 . Given that $f^{-1}(7)=1$, find the value of $a$ and of $b$.

25 (IB/sl/2015/May/paper2tz1/q4)
[Maximum mark: 7]
Let $f(x)=\frac{2 x-6}{1-x}$, for $x \neq 1$
 (a) For the graph of $f$ (i) find the $x$-intercept; (ii) write down the equation of the vertical asymptote; (iii) find the equation of the horizontal asymptote.
 (b) Find $\lim _{x \rightarrow \infty} f(x)$.

26 (IB/sl/2015/November/Paper1/q4)
[Maximum mark: 7 ]
Let $f(x)=3 \sin (\pi x)$.
 (a) Write down the amplitude of $f$.
 (b) Find the period of $f$.
 (c) On the following grid, sketch the graph of $y=f(x)$, for $0 \leq x \leq 3$. $[4]$

27 (IB/sl/2015/November/Paper1/q5)
[Maximum mark: 6]
Let $f(x)=(x-5)^{3}$, for $x \in \mathbb{R}$
 (a) Find $f^{-1}(x)$.
 (b) Let $g$ be a function so that $(f \circ g)(x)=8 x^{6}$. Find $g(x)$. [3]

28 (IB/sl/2015/November/Paper2/q3)
[Maximum mark: 7]
Let $f(x)=2 \ln (x-3)$, for $x>3 .$ The following diagram shows part of the graph of $f$
 (a) Find the equation of the vertical asymptote to the graph of $f$.
 (b) Find the $x$-intercept of the graph of $f$.
 (c) The region enclosed by the graph of $f$, the $x$-axis and the line $x=10$ is rotated $360^{\circ}$ about the $x$-axis. Find the volume of the solid formed. [3]

1 (a)(i) $\quad\left(0,-\frac{1}{3}\right)$ (ii) $x=-\frac{3}{2}$ (iii) $y=3$ (b) 3

2 (a) $c=-2$ (b) $y=-4$ (c) $k=4, k=0$

3 (a) $y$-intercept is $2.9$ (b) $x=2$ (c) $7.02$

4 (a) (i) $y=-1$ (ii) $x=2 \ln 2$ (iii) $y=-2$ (b) Graph

5 (a) $y=2$ (b) $f^{\prime}(x)=\frac{-1}{(x-1)^{2}}$ (c) $b=2$ (d) $a=e^{2}$ (e) $-1$

6 (a)(i) $f(0)=-\frac{1}{2}$ (ii) $f^{-1}(1)=2$ (b) $-2 \leqslant y \leqslant 2$ (c) Graph

7 (a) $h(x)=x^4-11$ (b) $x=\sqrt[3]{\frac{1}{4}}$

8 (a) $x=-3$ (b) $f^{-1}(x)=\frac{-3x-1}{x-2}$ (c) $y=-3$

9 (a) (i)$x=2$ (ii)$y=3$ (b) $\frac{16}{3}$

10 (a) $k=2,m=6$ (b) $10\le y\le 30$ (c)(i) $b=6,c=20$ (ii) $\frac{\pi}{3}$ (d) $3.82,4.03$

11 (a) $-0.25$ (b) $\iixi{4}{-1}$ (c) 1.03 (d) (i) $(f\circ f)(x)=x$(ii) $f^{-1}(x)=\frac{16}{x}$ (iii) 2.06 or $118^{\circ}$

12 (a) $f(1)=3$ (b) $(g \circ f)(1)=5$ (c) $g^{-1}(-2)=1$

13 (a) $\quad f(14)=4$ (b) 5 (c) $g^{-1}(x)=\frac{x+7}{3}$

14 $\frac{1}{20}$

15 (a) $0 \leqslant y \leqslant 7$ (b) (i) $f(2)=3$ (ii) $f^{-1}(2)=0$ (c) Graph

16 (a) $(g \circ f)(x)=2\left(1+e^{-x}\right)+b$ (b) $b=-5$

17 (a) $f^{\prime}(x)=\frac{x}{5}$ (b) $(f \circ g)(7)=250$

18 (a) $h(1)=18$ (b) $h^{\prime}(8)=14$

19 (a) $0 \leqslant y \leqslant 6$ (b) Graph (c) $-1 \leqslant x \leqslant 3$

20 (a) 8 (b) $(f\circ g)(x)=32x+3$ (c) $f^{-1}(x)=\frac{x-3}{8}$

21 (a) $h(x)=3 \sin (2 x)$ (b) $-3 \leqslant y \leqslant 3$

22 (a) $\quad x=0, x=1.74$ (b) $1.31$

23(a) $\bar{f}^{\prime}(-1)=5$ (b) $(f\circ f )(-1)=1$ (c) Graph
24(a) $a=4, b=3$
25(a) (i) $(3,0)$ (ii) $x=1$ (iii) $y=-2$ (b) $-2$
26(a) $3$ (b) 2 (c) Graph
27(a) $\quad f^{-1}(x)=\sqrt[3]{x}+5$ (b) $g(x)=2 x^{2}+5$
28(a) $x=3$ (b) $x=4$ (c) volume $=142$