Answer:
10.5 hours
Step-by-step explanation:
Given:
This week Andres will practice with his band for
on Monday
on Tuesday
2 hours Wednesday.
Next week Andres will practice with his band for the same number of hours on Monday, Tuesday, Wednesday.
<u>Question</u> <u>asked</u>:
What was the total number of hours Andres will practice with his band over these 6 days?
<u>Solution</u>:
As she practice for two weeks, three days of each week:
On two Monday, she will practice = 
On two Tuesday, she will practice = 
On two Wednesday, she will practice = 
Total hours, she will practice over 6 days 

Thus, Andres will practice 10.5 hours with his band over these 6 days.
0.377 + 5.51 = 5.887
Sorry I can only solve the first one. Could you give me a hint on how to do the second one ?
Answer:
C
Step-by-step explanation:
y = -f(x) is the reflection about the x-axis of the graph y = f(x).
Rearrange the equation as
cos(x) - √(1 - 3 cos²x) = 0
cos(x) = √(1 - 3 cos²x)
Note that both sides have to be positive, since the square root function is non-negative. If we end up with any solutions that make cos(x) < 0, we must throw them out.
Take the square of both sides.
(cos(x))² = (√(1 - 3 cos²(x))²
cos²(x) = 1 - 3 cos²(x)
4 cos²(x) = 1
cos²(x) = 1/4
cos(x) = ± √(1/4)
cos(x) = ± 1/2
We throw out the negative case and we're left with
cos(x) = 1/2
This has general solution
x = arccos(1/2) + 360° n or x = -arccos(1/2) + 360° n
(where n is any integer)
x = 60° + 360° n or x = -60° + 360° n
Now just pick out the solutions that fall in the interval 0° ≤ x < 360°.
• From the first solution set, we have x = 60° when n = 0.
• From the second set, we have x = 300° when n = 1.
So the answer is D.
Since BD is the perpendicular bisector of AC, then AB = BD, so:
6x = x+15
5x=15
x=3
CB = 3+15 = 18