Explore the values of tan A at several points on the line through the origin.[br]Then consider what this suggests about the definition of tan A.
Why did all four values of tangent turn out to be the same? Explain.
[list][*]Notice the similar triangles.[/*][*]Notice that the line through the origin has the form [math]y=m x[/math]. Then recall the definition of tangent.[/*][/list]
Which value of x is most suitable for defining tangent? Give your reasoning.
[list][*]Notice the definition of tangent.[/*][*]Recall that on the unit circle, the coordinates give the values of sine and cosine.[br][/*][/list]