2. Consider the parabola y = r. Any ray entering the parabola from above and traveling...

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2. Consider the parabola y = r. Any ray entering the parabola from above and traveling straight down (see Figure 3.22) will bounce off the parabola and pass through the focus point (0, 1/4) (the directrix is the line y = -1/4, as you can readily verify). Discuss this assertion in class. How would you determine the bounce of the ray? Think about the tangent line to the parabola at the point of impact. What does the tangent line have to do with the question? %3D 2. Consider the parabola y = r. Any ray entering the parabola from above and traveling straight down (see Figure 3.22) will bounce off the parabola and pass through the focus point (0, 1/4) (the directrix is the line y = -1/4, as you can readily verify). Discuss this assertion in class. How would you determine the bounce of the ray? Think about the tangent line to the parabola at the point of impact. What does the tangent line have to do with the question? %3D