Question

escrevam na forma algebrica os seguintes numeros complexos : a) 2 ( cos π/6+ i.sen π/6) b) 5 ( cós 0 + i.sen 0) c ) cos 3π/2 + i.sen 3π/2) d) 4 ( cos π + i.sen π) e) 2 ( cos π /4 + i.sen π /4)

Answer 1

Boa noite 

a) 

cos(pi/6) = cos(30) = √3/2
sen(pi/6) = sen(30) = 1/2

z = 2*(√3/2 + i/2) = √3 + i 

b)

cos(0) = 1
sen(0) = 0

z = 5*1 + 0i = 5

cos(3pi/2) = cos(135) = -√2/2
sen(3pi/2) = sen(135) = √2/2

z = (-√2 + √2i)/2 

d) 

cos(pi) = -1
sen(pi) = 0

z = 4*(-1 + 0i) = -4 

e)

cos(pi/4) = cos(45) = √2/2
sen(pi/4) = sen(45) = √272

z = 2*(√2 + i√)/2 = √2 + i