# Rate of Change of Slice Area

Calculus Level 5

A sphere has a radius of 10 units, and is centered at the origin. A sliding plane is defined by

$-\sin(\pi / 3) (y + 12 - (24/50) t) + \cos( \pi / 3 ) z = 0$

For a certain range of $$t$$ this plane crosses the sphere, and the intersection is a circle whose area is a function of $$t$$. Find the rate of change of the cross-sectional area at $$t = 15$$.

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