A-level · Algebra & functions

Inequalities on graphs and regionsExam-style questions

Reading an inequality as a region of the plane. The boundary as the matching equation; which side of a curve or line to shade, and testing a point; dashed boundaries for strict inequalities and solid ones for inclusive; a region as the overlap of several inequalities; finding its corners by solving the boundaries together; and writing down the inequalities for a shaded region.

18 questions · A-level level · mark scheme and worked solution on each · no sign-up to try

DifficultyAllLevel 2Level 3Level 4Level 5
  1. 1
    The inequality y>3x−2y > 3x - 2 defines a region of the plane.
    (a) Determine whether the point (2,5)(2, 5) lies in the region. (2 marks)
    (b) Determine whether the point (3,5)(3, 5) lies in the region. (1 mark)
    Level 2 · 3 marksTry it
  2. 2
    A student is asked to shade the region satisfying y>2x+1y > 2x + 1.
    (a) State whether the boundary line should be drawn solid or dashed, and why. (2 marks)
    (b) Describe how to decide which side of the line to shade. (1 mark)
    Level 2 · 3 marksTry it
  3. 3
    The diagram shows the curve y=9−x2y = 9 - x^2 and the line y=x+3y = x + 3. The region RR, shaded in the diagram, is bounded by the curve, the line and the xx-axis.Ry = 9 − x²y = x + 3xyWrite down three inequalities that define the region RR.

    (3 marks)
    Level 2 · 3 marksTry it