IMC 2007 Q12
12. Which of the following could be the graph showing the circumference \(C\) of a circle in terms of its diameter \(d\) ?
Intermediate Mathematical Challenge 2007, Question 12. © UK Mathematics Trust. Original paper on ukmt.org.uk
Answer: A
The formula which gives \(C\) in terms of \(d\) is \(C = \pi d\), so the graph of \(C\) versus \(d\) is a straight line which passes through the origin.
Solution © UK Mathematics Trust, from the IMC 2007 solutions.