IB DP Math MAA SL : IB Style Mock Exams – Set 4 Paper 1
Question
The graph of the function \(y = f(x)\) is defined for the domain \(-6 \le x \le 5\) as shown in the diagram below.

(a) Write down the value of \(f(-3)\).
(b) State the domain of \(f^{-1}\), the inverse function of \(f\).
(c) Find the value of \(x\) such that \(f^{-1}(2x – 7) = -3\).
▶️ Answer/Explanation
Detailed solution
(a)
From the graph, at \(x = -3\), the value of \(y\) is \(-1\).
\(f(-3) = -1\)
(b)
The domain of the inverse function \(f^{-1}\) is equivalent to the range of the original function \(f\).
The \(y\)-values on the graph range from \(-3\) to \(5\).
Domain: \([-3, 5]\)
(c)
If \(f^{-1}(2x – 7) = -3\), then by definition \(f(-3) = 2x – 7\).
Using the result from (a) where \(f(-3) = -1\):
\(-1 = 2x – 7\)
\(6 = 2x\)
\(x = 3\)
