Homework Statement
(x^2 + y^2)/a^2 + z^2/c^2 = 1
Homework Equations
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The Attempt at a Solution
the answer is :
b(θ) = R / (f^2 * tan^2(θ/2) + 1)^0.5
I can't understand how to calculate this.
My attempt :
(x^2 + y^2)/a^2 + z^2/c^2 = 1 from this.
b^2 + z^2/f^2 = a^2 , f = c/a, z =...