Its a , i had it yesterday and i got everything right dont worry :))
Answer:
•cos(s+t) = cos(s)cos(t) - sin(s)sin(t) = (-⅖).(-⅗) - (√21 /5).(⅘) = +6/25 - 4√21 /25 = (6-4√21)/25
•cos(s-t) = cos(s)cos(t) + sin(s)sin(t) = (-⅖).(-⅗) + (√21 /5).(⅘) = +6/25 + 4√21 /25 = (6+4√21)/25
cos(t) = ±√(1 - sin²(t)) → -√(1 - sin²(t)) = -√(1 - (⅘)²) = -⅗
sin(s) = ±√(1 - cos²(s)) → +√(1- cos²(s)) = +√(1 - (-⅖)²) = √21 /5
The answer would be around 4.5 or 4.6
The total ratio is 5
The number of comedy movies watched is 12
The number of other movies watched is 18
<h3>What is a ratio?</h3>
Ratio is a comparison of two or more numbers that indicates their sizes in relation to each other. Therefore,
He has watched 2 comedy movies for every 3 other movies. The total movies he has watched is 30. Therefore,
Ratio of comedy to total movies is as follows:
number of comedy movies watched = 2 / 5 × 30 = 60 / 5 = 12
number of other movies watched = 3 / 5 × 30 = 90 / 5 = 18
Therefore,
total ratio = 5
number of comedy movies watched = 12
number of other movies watched = 18
learn more on ratios here: brainly.com/question/10080852
