OCR C1 2012 January — Question 7

Exam BoardOCR
ModuleC1 (Core Mathematics 1)
Year2012
SessionJanuary
TopicCurve Sketching
TypeFind stationary points of polynomial

7 A curve has equation \(y = ( x + 2 ) \left( x ^ { 2 } - 3 x + 5 \right)\).
  1. Find the coordinates of the minimum point, justifying that it is a minimum.
  2. Calculate the discriminant of \(x ^ { 2 } - 3 x + 5\).
  3. Explain why \(( x + 2 ) \left( x ^ { 2 } - 3 x + 5 \right)\) is always positive for \(x > - 2\).