Question

dado sen x = - 3/2√3 e pi < x < 3pi/2, o valor de y = (1 + cos x) (1 - cos x) é:
A) -3/4
B) 3/4
C) ±3/4
D) 3/2

Answer 1

senx=-√3/2
sen²x=3/4

y=(1+cosx).(1-cosx)=1²-cos²x=1-cos²x=sen²x
y=sen²x
y=3/4