Answer:
c. 80
Step-by-step explanation:
cos x = sin(x-70)
cos x = cos [90-(x-70)]
cos x = cos (90-x +70)
cos x = cos 160 -x
x= 160-x
2x = 160
x =80
Answer:
k=9
Step-by-step explanation:

Answer:
B because the rotation of the wheel doesn't change the angle of the spokes.
It has to be the last one, D. I did it over 3 times to make sure.
Answer:
1/2
Step-by-step explanation:
if you look at a unit circle, sin(\pi/6) is
so cos of (\pi/6/2) would be \pi/3, and cos of (\pi/3) is 1/2