Google Classroom
GeoGebraGeoGebra Classroom

How can we explain equations for lines through the origin?

1) Play with the buttons to see what they do! 2) Put the third (alpha) button in the 0 degree position. 3) Put the second button C in a fixed position, and vary the first X button to a bunch of different values. Answer and discuss: How many of the X cm strip does it take to make the Y cm strip exactly? What does C tell you about how X and Y are related? See if you can write and explain an equation that relates X and Y. 4) Now move the third (alpha) button to the 90 degree position and repeat part 3. 5) Repeat parts 2, 3, and 4 but with a different fixed value for C. 6) Continue to repeat parts 2, 3, and 4 with different fixed values for C. 7) Discuss: what kinds of equations do lines through (0,0) have and why do they have that kind of equation?