Let α < β < Π / 2, sin α = 3 / 5, cos (α - β) = 12 / 13, then the value of sin β is () a.16/65 b.33/65 c.56/65 d.63/65

Let α < β < Π / 2, sin α = 3 / 5, cos (α - β) = 12 / 13, then the value of sin β is () a.16/65 b.33/65 c.56/65 d.63/65


Answer: (c)
The results show that sin α = 3 / 5, cos α = 4 / 5, cos (α - β) = 12 / 13, sin (α - β) = - 5 / 13
Therefore, sin β = sin [α - (α - β)] = sin α cos (α - β) - cos α sin (α - β) = (3 / 5) * (12 / 13) - (4 / 5) (- 5 / 13) = 56 / 65
Therefore, select (c)



In RT △ C = 90 °, ab = 13, BC = 5, then sin a, cos a, Tan a


sina=5/13 cosa=12/13 tana=5/12

Elden Ring Premiere

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