Respuesta :
Answer:
option b) cos 240 degrees.
Step-by-step explanation:
This means that the expression cos 120 degrees can also be written as cos 240 degrees.
This because cos 240 degrees = -1/2 = cos 120 degrees.
This happens because the second and third quadrants carry the same signs.
Read more on Brainly.in - https://brainly.in/question/5197628#readmore
The cos240 degree is equal to cos120 degree because they both have same value which is -1/2
What is trigonometry?
Trigonometry is a branch of mathematics that deals with the relationship between sides and angles of a right-angle triangle.
We have a:
= cos120°
The value of the cos120 is -1/2
= cos(90+30)
= -sin30
= -1/2
The value of cos240
cos240 = cos(180+60) = -cos60 = 1/2
cos120° = cos240°
Thus, the cos240 degree is equal to cos120 degree because they both have same value which is -1/2
Learn more about trigonometry here:
brainly.com/question/26719838
#SPJ2
