Give a geometric interpretation of the linear transformations defined by the matrices in Exercises 16 through 23. Show the effect of these transformations on the letter L considered in Example 5. In each case, decide whether the transformation is invertible. Find the inverse if it exists, and interpret it geometrically. See Exercise 13.

L3 - 2 3. Two basic triangles π/3 π/6 π/4 4. Unit circle (r =1 ,osi θ = y and cosθ = x) π/2 2π/3 π/3 3π/4 π/4 π/6 5π/6 π 0 7π/6 11π/6 5π/4 7π/4 4π/3 5π/3 3π/2 θ 0