We can clearly see line ‘a’ whose equation is y=mx+c. We can change the values of m and c using their corresponding slide bars. Observe how the position of this line changes as we change the values of m and c. Also observe how the angle α (between the line and the positive x-axis) changes with the change in values of m and c.

Questions to think about
Angle α (between the line and the positive x-axis) is given. Calculate tanα,what do we observe. Hint, compare tanα with m.
Look at the y intercept of the line and compare it with c. What do we notice?
Let’s fix the value of c and change the value of m, what do we observe?
Let’s fix the value of m and change the value of c, what do we observe?