Answer:
The value of cos Ф is ± 
Step-by-step explanation:
There are important rules for sin Ф and cos Ф
∵ sin Ф = 
∴ sin²Ф = 
∴ sin²Ф = 
→ By using the third rule above
∵ cos²Ф = 1 - sin²Ф
∴ cos²Ф = 1 - 
∴ cos²Ф = 
→ Take square root for both sides
∴ cos Ф = ± 
∴ The value of cos Ф is ± 
Answer:
Mean = 19.5
Step-by-step explanation:
Mean = sum of numbers ÷ Amount of numbers
Mean = 
Mean = 
Mean = 19.5
Answer:
take a screen shot and then post it
Step-by-step explanation:
mark me brainlist
Answer:
1800 liters
Step-by-step explanation:
150*150*80=1800000 cubic cm
1800000/1000= 1800 liters
Might seem like a lot but really isn't.