Gradient
You can change the gradient (a) and y-intercept (b), you can drag the point P with the mouse or with the P.x spinner. Watch the visual and numerical representation of the gradient ... You can change the scale and you can pan horisontally with 0.x and vertically with 0.y. If you left-click with the mouse, the coordinates of the point is shown ...
Note: If the applet becomes smudged, click on the "Init" button (for Initialise or reset).
Find the gradient
You should see a red point on the grid. Now change the equation of the given line, so that the line passess through the point and press ENTER. (You may use decimals or fractions. Note that you can read co-ordinates from the grid with a mouse-click.) A new point should appear. If not, the generated point is out of range, so simply press ENTER again. You should be able to find the equation of 8 successive points correctly!
Inequalities
Move point P with the mouse to see where in the plane ax + by > c, ax + by = c or ax + by < c. Change a, b and c and check again ...
Find the equations
Change the equations of the three lines so that it forms a triangle PQR. (Type your change and then press ENTER.)
Simultaneous linear equations
If the intersection falls is not visible, you can Zoom out by changing the scale ... Also, you can click in the graph to see co-ordinates,
Trig definition
Self explanatory! Note that the angle is not restricted ... so try negative angles, or angles bigger that 360.
Trig graphs ...
Click repeatedly (lean) on the Angle spinner, or type an angle in the input box and press ENTER. Try panning by leaning on 0.x ...
Altitudes
Drag points A, B and C and see how altitudes change.
Check the equations of the altitudes ...
Prove that the altitudes are concurrent.
The reflective property of the parabola