Hi, I've been attempting this problem for a while now, but I just can't seem to work it out.
A spotlight has parabolic cross sections.
a) Write an equation for a cross section of the spotlight if the bulb is 15 centimeters from the vertex and the vertex is placed at the origin.
I was able to figure this part out: y=(1/60)x^2
b) If the spotlight has a diameter of 72 centimeters at its opening, find the depth of the spotlight if the bulb is 15 centimeters from the vertex.
I know the answer is supposed to be 21.6 cm, but I'm not quite sure how to arrive at it. I'm also not sure what is meant by "its opening".
Could anyone suggest a method to solve the problem? Thanks for your help!
A spotlight has parabolic cross sections.
a) Write an equation for a cross section of the spotlight if the bulb is 15 centimeters from the vertex and the vertex is placed at the origin.
I was able to figure this part out: y=(1/60)x^2
b) If the spotlight has a diameter of 72 centimeters at its opening, find the depth of the spotlight if the bulb is 15 centimeters from the vertex.
I know the answer is supposed to be 21.6 cm, but I'm not quite sure how to arrive at it. I'm also not sure what is meant by "its opening".
Could anyone suggest a method to solve the problem? Thanks for your help!
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