Question

Sendo sen x =0,5 e y =pi/2, calcule sen (x-2y).

Answer 1

Oi Cecila

sen(x) = 1/2
cos(x) = √3/2

sen(y) = 1, sen(2y) = 0
cos(y) = 0, cos(2y) = -1

sen(x - 2y) = sen(x)*cos(2y) - cos(x)*sen(2y) 
sen(x - 2y) = 1/2 * -1 - √3/2 * 0 = -1/2 

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