好像是要用微積分...?不清楚想問一下
d d -1/2
[1+(----)^2 - ---cosx]
2R R
~ d d^2 3cos^2x - 1
= 1 + ----cosx + ---- -----------
2R 4R^2 2
上式如何化簡成下式的?
謝謝!
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