Pearson Edexcel International GCSE (9–1) · MATHEMATICS A · Unit
Unit 8
106 practice questions
Topics covered
Practice questions
21–30 of 106
Question 21
2 marks · Easy
Answer and see the solution →Let and . Explain, step by step, how to find the value of the composite function , and then work it out.
Question 22
3 marks · Easy
Answer and see the solution →Let the function f be defined as .
(a)[1 mark]Write down the equation to find the inverse function .
(b)[1 mark]Find the inverse function .
(c)[1 mark]Find .
Question 23
3 marks · Easy
Answer and see the solution →The table shows a mapping from set X to set Y.
Mapping Table X Y 0 2 2 6 5 12 8 18 (a)[1 mark]Does this mapping represent a function? Give a reason.
(b)[1 mark]Write the rule for the function as an expression for Y in terms of X.
(c)[1 mark]Use your rule to find the value of Y when X = 10.
Question 24
1 mark · Easy
Answer and see the solution →State the range of the function , when the domain is .
Question 25
2 marks · Easy
Answer and see the solution →Let and . Find the value of .
Question 26
2 marks · Normal
Answer and see the solution →Write down, giving a reason, whether the following mapping represents a function.
Mapping Table x y −2 4 1 3 3 5 Question 27
3 marks · Normal
Answer and see the solution →Let the function f be defined by f(x) = 3x - 5 with domain {2, 4, 5, 7}.
Find the range of f.
Question 28
3 marks · Normal
Answer and see the solution →Let f(x) = 2x + 1 and g(x) = x^2.
Explain how to find the value of the composite function fg(3), and work it out.
Question 29
4 marks · Normal
Answer and see the solution →The function f is defined by f(x) = 4x + 1.
a) Show, by algebraic method, how to find the inverse function f^{-1}(x).
b) Use your result to find f^{-1}(13).
(a)[3 marks]Show, by algebraic method, how to find the inverse function f^{-1}(x).
(b)[1 mark]Use your result to find f^{-1}(13).
Question 30
4 marks · Normal
Answer and see the solution →The following table gives the mapping from numbers in set P to set Q.
Mapping Table P Q 1 −2 2 0 3 2 4 4 For this mapping:
(a)[1 mark]Is this mapping a function? Give a reason.
(b)[2 marks]Write down the domain and range of the mapping.
(c)[1 mark]Is this function one-to-one or many-to-one? Explain.