Respuesta :
Answer:
A
Step-by-step explanation:
cos(x)=2/3 in Q 4
sin(x/2)=+√(1-cos(x))/2
√(1-cos(x))/2=√(1-[2/3]/2=√(1/3)/2=-√(1/6) because sin is negative in Q 4
Answer:
See below.
Step-by-step explanation:
Because cos x = 2/3 the adjacent side = 2 and hypotenuse = 3 so the length of the opposite side =
√(3^2 - 2^2) = -√5 (its negative because we are in Quadrant 4).
So sin x = -√5/3.
(a) sin (x /2) = - √ [ (1 - cos x)/2 ]
= -√(1 - 2/3)/ 2)
= -√(1/6). or -0.4082.
(b) cos (x/2) = √ [ (1 + cos x)/2]
= √ 5/6 or 0.9129.
(c) tan (x /2) = ( 1 - cos x) / sin x.
= ( 1 - 2/3) / -√5/3
= -0.4472.
