Sketch a curve

Your instructor might ask that you sketch a curve as part of an activity.

If a question requires you to sketch a curve, the Sketch Board and Sketch Board toolbar will be available within the question.

A blank Sketch Board with a full Sketch Board toolbar.

The Sketch Board is comprised of a set of tools that can be used to create and interact with various types of curve sketches.

Some example curve sketching questions are:

  • Graph a single or multiple lines or curves.
  • Indicate which region represents the solution set (single line or curve, multiple lines or curves).
  • Make the line solid or dashed to indicate whether the line is in the solution set.
  • Remove the portion of the line or curve that does not belong.
  • Use an open or closed circle to indicate whether the endpoints belong.
  • Add asymptotes to logarithmic and exponential curves.

Curve sketching tasks

There are 15 possible tools that can be found in your Sketch Board toolbar for you to use to sketch a curve.

Your instructor can choose which set of tools appear in the Sketch Board toolbar.

The full Sketch Board toolbar showing all possible tools.

NOTE: Your instructor might choose to include more drawing tools in the toolbar than you need that act as distractors. This can be done to test if you'll make the correct selection(s).

To use a tool from the toolbar, click on it so that it becomes highlighted.

A selected Sketch Board toolbar tool appears highlighted in red.

TIP: Click a highlighted tool on the toolbar to deselect it or click on a different tool.

NOTE: Your instructor can define whether you're permitted to use a tool multiple times on your Sketch Board. Example — Your instructor could define a rule in Möbius that, when using the Plot Dropline Point toolThe "Plot Dropline Point" icon is a point with two lines extending from it at 90 degrees., you're only allowed to plot one point on your Sketch Board. This means that you can only plot a single point with the Plot Dropline Point toolThe "Plot Dropline Point" icon is a point with two lines extending from it at 90 degrees. but won't be able to select the tool again to plot a second point.

TIP: Hover your cursor over a plotted point to reveal its exact coordinates as an ordered pair (x-coordinate, y-coordinate).

The cursor is hovered over a plotted point on the Sketch Board and the coordinates appear.

Plot a single point

You can plot individual points on the Sketch Board's coordinate grid.

To plot a single point:

  1. Click Plot Dropline PointThe "Plot Dropline Point" icon is a point with two lines extending from it at 90 degrees..

  1. Click on the Sketch Board coordinate grid where you want your single point plotted.

A single point is plotted on the Sketch Board.

TIP: Click-and-drag the plotted point to a new location if you want to move it.

Graph a line

Graphing a line enables you to plot points on the Sketch Board's coordinate grid.

To graph a line:

  1. Click Draw LineThe "Draw Line" icon is 2 points with a single straight line going through them..

  1. Plot two points on the coordinate grid. After you plot two points on the grid, a line is drawn through these points.

2 points are plotted with a single stright line going through them.

TIP: Click-and-drag the plotted points or the line to a new location if you want to move them.

Graph absolute values

You can plot the vertex and an additional point on the coordinate grid.

To graph an absolute value:

  1. Click Draw Absolute ValueThe "Draw Absolute Value" icon is 2 points with a line going through them, but one of the points is a vertex..

  1. First plot the vertex.

A plotted single point on the Sketch Board.

  1. Plot the second point next. The absolute value graph is drawn automatically.

A seond point is plotted on the Sketch Board and the line with a vertex passes through the two points.

TIP: Click-and-drag either of the two points anywhere on the grid to stretch, compress, reflect, or translate the absolute value.

Graph a parabola

Graphing a parabola enables you to plot points on the Sketch Board's coordinate grid that you can reshape and reposition.

To graph a parabola:

  1. Click Draw Vertex-Point ParabolaThe "Draw Vertex-Point Parabola" icon is a parabola with two points..

  1. First plot the vertex on the coordinate grid.

A single point is plotted on the Sketch Board as the parabola vertex.

  1. Graph your second point. After you plot two points on the grid, a curve is drawn through these points.

A second point is plotted on the Sketch Board and a parabola is automatically drawn through the points.

TIP: Click-and-drag either of the points anywhere on the grid to stretch, compress, reflect, or translate the parabola.

TIP: You can also click Draw Three-Point ParabolaThe "Draw Three-Point Parabola" icon is a parabola with three points. or Draw Three-Point Parabola SegmentThe "Draw Three-Point Parabola Segment" icon is a parabola segment with three points.. The order in which these points are placed isn't relevant since the Sketch Board will automatically draw the curve with the vertex at the middle point.

Graph exponential curves

You can plot two points and a horizontal asymptote to create an exponential curve.

To graph an exponential curve:

  1. Click Draw ExponentialThe "Draw Exponential" icon is a 2-point curve approaching a horizontal asymptote..

  1. Plot two points on the exponential curve.

Two points that will make up the curve are plotted on the Sketch Board.

  1. Click the location on the coordinate grid where you want to place the horizontal asymptote for the curve. A dashed horizontal line is automatically drawn through the point on the grid where you clicked.

The cursor was placed below the plotted points and the dotted horizontal asymptote appears. The two points have a curve drawn through them.

TIP: Click-and-drag the horizontal asymptote to a new location if you want to move it.

Graph logarithmic curves

You can plot two points and a vertical asymptote to create a logarithmic curve.

To graph a logarithmic curve:

  1. Click Draw LogarithmicThe "Draw Logarithmic" icon is a curve with two points approaching a vertical asymptote..

  1. Plot two points on the logarithmic curve.

Two points that will make up the curve are plotted on the Sketch Board.

  1. Click the location on the coordinate grid where you want to place the vertical asymptote. A dashed vertical line is automatically drawn through the point on the grid where you clicked.

The cursor was placed to the left of the plotted points and the dotted vertical asymptote appears. The two points have a curve drawn through them.

TIP: Click-and-drag the vertical asymptote to a new location if you want to move it.

Indicate a region of the graph

Indicating which region on the graph represents the solution set enables you to select a region on either side of a single line or select a region bounded by two lines.

To indicate a region of the graph:

  1. Click Choose RegionThe "Choose Region" icon is a shaded triangular space formed by three intersecting lines..

  1. Click anywhere inside the region that represents the solution set to the problem. The region becomes shaded.

The cursor is placed below a graphed line on the Sketch Board and the region enclosed by the line becomes shaded.

Remove a portion of a line or parabola

You can remove a portion to the left or right of a parabola.

To remove a portion of a line or parabola:

  1. Click Snip LeftThe "Snip Left" icon is a pair of scissors cutting a line to the left of a plotted point. or Snip RightThe "Snip Right" icon is a pair of scissors cutting a line to the right of a plotted point..

  1. Click on the portion of the parabola you want to keep. The portion to the left or right of your cursor (depending on the selected control) is removed.

A plotted curve is missing a portion to the right of a plotted point.

NOTE: If you selected Snip Left The "Snip Left" icon is a pair of scissors cutting a line to the left of a plotted point., the portion of the parabola to the left of your cursor is removed. Similarly, if you selected Snip Right The "Snip Right" icon is a pair of scissors cutting a line to the right of a plotted point., the portion of the parabola to the right of your cursor is removed.

Remove a portion of a line or parabola between two points

You can remove a portion of a parabola between two selected points.

To remove a portion of a line or parabola:

  1. Click Snip BetweenThe "Snip Between" icon is a pair of scissors cutting the line between two plotted points..

  1. Select two points on the parabola by clicking on them. A green point indicates each selected location. The portion of the parabola between these two green points is automatically removed.

A portion of a curve is removed between the two selected points that are plotted on the Sketch Board.

Include or exclude endpoints

You can toggle back and forth between filled (included) and open (excluded) endpoints.

To indicate the position of endpoints on the graph:

  1. Click Toggle Filled/HollowThe "Toggle Filled/Hollow" icon shows a filled point and a hollow point separated by a bidrectional arrow..

  1. Click on the endpoint that you want to include (fill) or exclude (open).

The endpoint of a line segment is green and hollow on the Sketch Board.

TIP: If the endpoint is filled (included), click on it to make it open (excluded). Similarly, if the endpoint is open (excluded), click on it to make it filled (included).

Make solid or dashed lines for a graph

You're able to switch between solid and dashed lines interchangeably.

To use solid or dashed lines for a graph:

  1. Click Toggle Solid/DashedThe "Toggle Solid/Dashed" icon is a solid line and a parallel dashed line separated by a bidirectional arrow..

  1. Click on a line. If the line was solid, then the entire line becomes dashed.

The cursor is over top of a plotted dashed curve on the Sketch Board.

TIP: To change the line back to solid, click the line again and it will revert back to its original state.

Delete a line

Any line that you have sketched can be deleted.

To delete a line:

  1. Click DeleteThe "Delete" icon is a trash can..

  1. Hover your cursor over the item you want to delete. The item becomes highlighted.

The cursor is hovering over a plotted point on the Sketch Board.

  1. Click the highlighted item and it will be deleted from your Sketch Board.