Answer:
cos(300)
Step-by-step explanation:
you must use the identity:
cos(a+b)=cos a cos b - sin a sin b
In this case a=140 and b=540. Hence, the answer is
cos(140+520)
or
cos(660)
However, it's about a round and a half to the circle,
hence, 660 is the same as 660-360=300.
Finally, the answer is cos(300)
