A-LevelMathematicsLogarithmic and exponential functions9709/21 · May/June 2022 · Q14 Marks

The variables x and y satisfy the equation y = 4^(2x-a), where a is an integer. As shown in the diagram, the graph of ln y against x is a straight line passing through the point (0, -20.8), where the second coordinate is given correct to 3 significant figures.

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.

Mark scheme

Marking points from the official mark scheme (May/June 2022). The mark or mark type is shown in brackets.

[1] State or imply equation is ln y = (2x – a) ln 4 OE. Do not condone poor use of brackets.
[1] AG – necessary detail needed
[1] Substitute for ln y and attempt value of a
[1] Integer answer required, but condone 15.0

On Oracle Prep you can write or photograph your own answer and have it marked by AI against this mark scheme, with feedback on what you missed.

Topic: Logarithmic and exponential functions, A-Level Mathematics (syllabus 9709). Structured question, 4 marks.
Source: A-Level Mathematics, May/June 2022 Paper 2 Variant 1, question 1.

Questions and mark schemes are from past examination papers and remain the copyright of the exam board. How Oracle Prep builds its content