Tutorial Plotting

Plotting

Enter and plot a function

Scale the y-axis

Change a plot's color

Find points of intersection

Plot a family of functions

Plot an implicitly defined curve

Plot an inequality

Plot an ellipse

Plot a function using constants

Plot a family of functions using an iterated constant

To plot the function y = x/(x^2 - 4) on the interval -4 x 4,

Select New Function from the Work menu.
y1(x) = will appear as the first entry in the Work window.
Type the expression x/(x^2-4) into the first cell of the Work window. Press the Enter or Return key.
Click in the Domain & Range window to make it active. Click in the cell to the left of “ x ” and type -4. Press Tab to move to the cell to the right of “ x ” and then type 4.
Select Plot from the Graph menu. Note that TEMATH automatically scales the y-axis to fit the graph and displays the vertical asymptotes.

Topic Start

Section Start

If you want to specify your own scaling for the y-axis, for example, -5 y 5,

Click in the Domain & Range window to make it active. Click in the cell to the left of “ y ” and type -5. Press Tab to move to the cell to the right of “ y ” and then type 5.
Click in the Autoscaling checkbox to turn off autoscaling.
Select Plot from the Graph menu.

Topic Start

Section Start

To change the color of the plot,

Click in the Work window to make it active.
Click on the vertical line to the left of the function in the Work window. Each time you click, a new color will be shown. TEMATH provides five different colors for plotting. Select the color that you want.
Select Plot from the Graph menu.

Topic Start

Section Start

To find the points of intersection of the curves y = x/(x^2 - 4) and y = x^2 - 4,

Select New Function from the Work menu.
y2(x) = will appear as the first entry in the Work window.
Type the expression x^2-4 into the first cell of the Work window. Press the Enter or Return key.
Select Overlay Plot from the Graph menu.
Click on the Curve Intersection tool on the tool palette in the Graph window. It is the ninth tool from the left and it shows the intersection of two curves. The tool's icon will become highlighted.
Click in the Graph window near a point of intersection. The coordinates of the point of intersection will be written into the Report window and a point with displayed coordinates will be drawn at the position of the intersection of the two curves.
Click near the second point of intersection.

Topic Start

Section Start

To plot the family of functions: y = x^2, y = x^2 + 1, and y = x^2 + 2,

Select New Function from the Work menu.
Type the expression x^2 into the first cell of the Work window. Press the Enter or Return key.
Select New Function from the Work menu.
Type the expression x^2 + 1 into the first cell of the Work window. Press the Enter or Return key.
Select New Function from the Work menu.
Type the expression x^2 + 2 into the first cell of the Work window. Press the Enter or Return key.
If you've plotted the previous two functions in this section, click on the checkmark to the left of those two functions in the Work window. The checkmarks will disappear and the two functions will be deactivated.
Select Plot All from the Graph menu. All the checked (active) functions will be plotted in the Graph window.

Topic Start

Section Start

To plot the implicit equation x^2 + y^3 = 4 on -5 x 5 and -5 y 5,

Select New Equation or Inequality from the Work menu.
Type the expression x^2 + y^3 = 4 into the first cell of the Work window. Press the Enter or Return key.
Click in the Domain & Range window to make it active. Enter the domain -5 x 5 and the range -5 y 5.
Select Plot from the Graph menu.

Topic Start

Section Start

To plot the inequality 2x + 5y 4,

Select New Equation or Inequality from the Work menu.
Type the expression 2x + 5y 4 into the first cell of the Work window (for , type Option < or enter using a pop-up menu).
Press the Enter or Return key.
Select Plot from the Graph menu.

Topic Start

Section Start

To plot the ellipse (x-1)^2/(3^2) + (y+1)^2/(2^2) = 1,

Select Conic — Ellipse from the Work menu.
Fill-in the template e#: ellipse(1,3,-1,2) in the first cell of the Work window. Press the Enter or Return key.
Select Plot from the Graph menu.

Topic Start

Section Start

To plot a function using constants,

Select New Constant from the Work menu.
c1 = will appear as the first entry in the Work window.
Delete c1 = and type the expression m = 3. Press the Enter or Return key.
Select New Constant from the Work menu.
c2 = will appear as the first entry in the Work window.
Delete c2 = and type the expression b = -2. Press the Enter or Return key.
Select New Function from the Work menu.
Type the expression m x + b into the first cell of the Work window. Be sure to type a space between the m and the x. Press the Enter or Return key.
Select Plot from the Graph menu.

Topic Start

Section Start

To plot a family of functions using an iterated constant,

Select the cell containing b = -2 in the Work window.
Delete its contents and type the expression b = -2 to 2. Press the Enter or Return key.
Select Plot from the Graph menu. Five lines will be plotted in the Graph window for b = -2, -1, 0, 1, 2.

Topic Start

Section Start

Previous Section

Next Section