I think it's 0 since anything multiplied by 0 is, well, 0! No matter what the sign is. I believe the correct answer is 0 :)
This is a simple consequence of the Zero-sum problem: https://en.wikipedia.org/wiki/Zero-sum_problem
Answer: Fourth option is correct.
Step-by-step explanation:
Since we have given that
Timothy scored 83 out of 100.
His percentile rank in his class = 72
Clayton scored 85 out of 100.
His percentile rank in his class = 70.
Since Clayton's percentile rank is lower than Timothy's rank.
So, Timothy performed better with respect to the rest of the students in the class.
Hence, Timothy as his percentile score is higher.
Therefore, Fourth option is correct.
Answer:
(d). 
Step-by-step explanation:
sin² β + cos² β = 1
cos (α + β) = cos α cos β - sin α sin β
cos α = √(1 - 
) = 21 / 29
cos β = 12 / 13
sin β = √(1 - 
) = 5 / 13
sin α = 20 / 29
cos (α + β) = 
× 
- 
× 
=
