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
Answer: 
Step-by-step explanation:
This is a multiplication problem. You are multiplying
by 4. This also means 4 divided by 3. They are both the same.
The answer is c. 0.10. Week 4 is plotted at 0.35 and Week 2 is plotted at 0.25. Difference means subtract. 0.35 - 0.25 = 0.10. Hope this helps!
Answer:

Step-by-step explanation:

- First, lets get rid of the fraction. I did this by multiplying both sides by
.

- We want to isolate
on one side of this equation. Let's put any values with
on one side of the equation, and normal integers on the other.

- Divide both sides by
.

- If your teacher wants you to leave your final answer as an improper fraction, your final answer is this. If they want it to be a mixed number or decimal, your final answer will be:
