(3+sin60)/(2-sin^2 15度)的值

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(3+sin60)/(2-sin^215度)的值(3+sin60)/(2-sin^215度)的值(3+sin60)/(2-sin^215度)的值sin^2(a/2)=(1-cos(a))/2sin^2

(3+sin60)/(2-sin^2 15度)的值
(3+sin60)/(2-sin^2 15度)的值

(3+sin60)/(2-sin^2 15度)的值
sin^2(a/2)=(1-cos(a))/2 sin^2(15/2)=(1-cos(30))/2 =(1/2-根号(3)/4)
(3+sin60)/(2-sin^2 15度)=(3+根号(3)/2)/[2-(1/2-根号(3)/4)]
=(6+根号3)/(3+根号(3)/2)
=2

sin60=1/2
sin15平方=(1-cos30)/2 (半角公式)
一代就行了