Question

x = pi/2 rad sen x/2 - 3 * sen 2x + sen 3x / 4

Answer 1

Oi 

x = pi/2 = 90°

sen(x/2) = sen(45°) = √2/2

sen(2x) = sen(180°) = 0

sen(3x) = sen(270°) = -1

E = sen(x/2) - 3sen(2x) + sen(3x)/4 

E = √2/2 - 3*0 - 1/4 = (2√2 - 1)/4 

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