sin75度+sin15度等于多少?

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sin75度+sin15度等于多少?

sin75度+sin15度等于多少?
sin75度+sin15度等于多少?

sin75度+sin15度等于多少?
sin75+sin15=2sin(90/2)cos(60/2)=2*√2/2*√3/2=√6/2

sin(A/2)=√[(1-cosA)/2]
sin75°+sin15°=√[(1-cos150°)/2]+√[(1-cos30°)/2]
=√6/2

根号6/2

sin75°+sin15°
=2sin45°cos30°
=2×√2/2×√3/2
=√6/2
sin75°+cos75°

sin75+sin15
=sin(45+30)+sin(45-30)
=sin45cos30+cos45sin30+sin45cos30-cos45sin30
=2*sin45cos30
=2*(根号2/2)*(根号3/2)
=根号6/2