Quandaries and Queries


Who is asking: Student
Level: Secondary

i am trying to find the equation for a mirror for a laser experiment. the mirror is parabolic but my question is how do you find the equation when you know only the focus and the diameter the mirror diameter is 520 mm and the focus is at 1024 mm. would you just use the measurements in the equation instead of "nice numbers" or what.



Hi Nathan,

I am going to think of the parabola as opening upwards with its vertex at the origin. The equation of the parabola is then

y = 1/4p x2

where p is the distance from the vertex to the focus. Since, in your case, p = 1024, the equation is

y = 1/4096 x2



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