OCR MEI C2 2012 January — Question 3 3 marks

Exam BoardOCR MEI
ModuleC2 (Core Mathematics 2)
Year2012
SessionJanuary
Marks3
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicStationary points and optimisation
TypeFind range where function increasing/decreasing
DifficultyModerate -0.8 This is a straightforward application of differentiation to find where a function is decreasing. Students need only differentiate a simple quadratic, set f'(x) < 0, and solve a linear inequality—all routine C2 skills with no problem-solving required.
Spec1.07i Differentiate x^n: for rational n and sums1.07o Increasing/decreasing: functions using sign of dy/dx

3 Find the set of values of \(x\) for which \(x ^ { 2 } - 7 x\) is a decreasing function.

3 Find the set of values of $x$ for which $x ^ { 2 } - 7 x$ is a decreasing function.

\hfill \mbox{\textit{OCR MEI C2 2012 Q3 [3]}}