IBDP Maths SL 2.6 The quadratic function AA HL Paper 2- Exam Style Questions- New Syllabus
Question
Let \(f\) be a quadratic function. Part of the graph of \(f\) is shown below.
The vertex is at P(\(4\), \(2\)) and the y-intercept is at Q(\(0\), \(6\)) .
a.Write down the equation of the axis of symmetry.[1]
b.The function f can be written in the form \(f(x) = a{(x – h)^2} + k\) .
Write down the value of h and of k .[2]
c.The function f can be written in the form \(f(x) = a{(x – h)^2} + k\) .
Find a .[3]
▶️Answer/Explanation
Markscheme
\(x = 4\) (must be an equation) A1 N1
[1 mark]
\(h = 4\) , \(k = 2\) A1A1 N2
[2 marks]
attempt to substitute coordinates of any point on the graph into f (M1)
e.g. \(f(0) = 6\) , \(6 = a{(0 – 4)^2} + 2\) , \(f(4) = 2\)
correct equation (do not accept an equation that results from \(f(4) = 2\) ) (A1)
e.g. \(6 = a{( – 4)^2} + 2\) , \(6 = 16a + 2\)
\(a = \frac{4}{{16}}\left( { = \frac{1}{4}} \right)\) A1 N2
[3 marks]