Answer:
-sqrt(2)/2
Explanation:
did the test
-sqrt(2)/2 , the last option of your document.
sin(7pi/4) = -sin(7pi/4 - pi)
= -sin(7pi/4 - 4pi/4)
= - sin(3pi/4)
sin(3pi/4) is a special angle , which is sqrt(2)/2
Hence, sin(7pi/4) = -sin(3pi/4)
= -sqrt(2)/2
8.8m questions
11.4m answers