Name _____________________________________________ Chapter 4 – Functions review
1. Consider f(x) = x 5 .
(a) Find
(i) f(11);
(ii) f(86);
(iii) f(5).
(3)
(b) Find the values of x for which f is undefined.
(2)
(c) Let g(x) = x2. Find (g ° f)(x).
(2)
(Total 7 marks)
x4
2. Let f (x) = , x − 4 and g (x) = x2, x .
(a) Find (g ◦ f ) (3).
(b) Find f −1(x).
(c) Write down the domain of f −1.
(Total 6 marks)
3. The functions f and g are defined by f : 3x, g : x x 2 .
(a) Find an expression for (f g) (x).
(b) Show that f –l (18) + g–l (18) = 22.
(Total 6 marks)
IB Questionbank Maths SL 1
4. Consider the graph of f shown below.
(a) On the same grid sketch the graph of y = f(–x).
(2)
The following four diagrams show images of f under different transformations.
(b) Complete the following table.
Description of transformation Diagram letter
Horizontal stretch with scale factor
1.5
Maps f to f(x) + 1
(2)
IB Questionbank Maths SL 2
(c) Give a full geometric description of the transformation that gives the image in Diagram A.
(2)
(Total 6 marks)
5. The function f is given by f (x) = 1n ( x 2) . Find the domain of the function.
Working:
Answer:
.....................................................................
.
(Total 4 marks)
6. Let f(x) = 7 – 2x and g(x) = x + 3.
(a) Find (g ° f)(x).
(2)
(b) Write down g–1(x).
(1)
(c) Find (f ° g–1)(5).
(2)
(Total 5 marks)
7. Let f(x) = 3x2. The graph of f is translated 1 unit to the right and 2 units down.
The graph of g is the image of the graph of f after this translation.
(a) Write down the coordinates of the vertex of the graph of g.
(2)
(b) Express g in the form g(x) = 3(x – p)2 + q.
(2)
IB Questionbank Maths SL 3
The graph of h is the reflection of the graph of g in the x-axis.
(c) Write down the coordinates of the vertex of the graph of h.
(2)
(Total 6 marks)
1 3
x x 2 3x
8. Let f(x) = 3 . Part of the graph of f is shown below.
There is a maximum point at A and a minimum point at B(3, –9).
(a) Find the coordinates of A.
(8)
(b) Write down the coordinates of
(i) the image of B after reflection in the y-axis;
2
(ii) the image of B after translation by the vector 5 ;
(iii) the image of B after reflection in the x-axis followed by a horizontal stretch with
1
scale factor 2 .
(6)
(Total 14 marks)
IB Questionbank Maths SL 4