Graphs 6
3 marks · NormalThe graph of is drawn for .
Explain how you can estimate, from the graph, the value of when , and describe the process for doing this accurately.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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Must show: Draw a horizontal line y=2.5, Find x where the graph crosses this line, State x-values correspond to these intersection points
Also accept: Correctly describes reading x for y=2.5 on the graph
Common mistakes: Looking for y=2.5 as a maximum or minimum; Ignoring intersection points
Show mark scheme and worked solution
Marking points
B1 · 1 mark · States or describes drawing a horizontal line at y=2.5.
B2 · 1 mark · Identifies the intersection points of the curve and the line.
B3 · 1 mark · Explains that the corresponding x values at these points are the solutions.
Worked solution
Draw a horizontal line across the graph at y = 2.5. Mark the points where this line crosses the curve of y = 10/x + x - 5. The x-values at these intersections are the solutions to y = 2.5. These can be read from the x-axis beneath each intersection.