# trig

find the exact value by using the appropriate half-angle identity:

sin(5pi/12)

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1. Some students can "think" better in degrees than radians, so 5π/12 rd = 75°

sin75 = sin(30+45)
= sin30cos45 + cos30sin45
= (1/2)√2/2 + (√3/2)(√2/2)
= (√2 + √6)/4

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posted by Reiny

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