A Cross-Section of a Parabolic Reflector Is Shown in the Figure

question 52

Multiple Choice

A cross-section of a parabolic reflector is shown in the figure. The bulb is located at the focus and the opening at the focus is $18 \mathrm {~cm}$ . Find an equation of the parabola. Let $V$ be the origin. Find the diameter of the opening $| C D | , 19 \mathrm {~cm}$ from the vertex.

• A) \(| C D | = 6 \sqrt { 38 }\)
• B) \(| C D | = 18\)
• C) The equation is \(y = 18 x ^ { 2 }\)
• D) \(| C D | = 4 \sqrt { 414 }\)
• E) The equation is \(y ^ { 2 } = 18 x\)
• F) The equation is \(y ^ { 2 } - \frac { x ^ { 2 } } { 18 } = 1\)

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