Corrected Question
The volume of air inside a rubber ball with radius r can be found using the function V(r) = four-thirds pi r cubed. What does V(5/7) represent?
Answer:
(B)the volume of the rubber ball when the radius equals five-sevenths feet
Step-by-step explanation:
The Volume of a sphere of radius r can be found using the formula:

Therefore comparing the expression:
with V(r):

Thus,
is the volume of a ball of radius
feet.
The correct option is B.
Answer:
cos(a + b) = 
Step-by-step explanation:
cos(a + b) = cos(a).cos(b) - sin(a).sin(b) [Identity]
cos(a) = 
cos(b) = 
Since, terminal side of angle 'a' lies in quadrant 3, sine of angle 'a' will be negative.
sin(a) =
[Since, sin(a) =
]
= 
= 
Similarly, terminal side of angle 'b' lies in quadrant 2, sine of angle 'b' will be negative.
sin(b) =
= 
= 
By substituting these values in the identity,
cos(a + b) = 
= 
= 
= 
Therefore, cos(a + b) = 
Answer:
Step-by-step explanation:
Part A
Since, the given angles are formed at a point are on a straight line, sum of these angles will be 180°.
Part B
(3x - 5)° + (4x + 2)° + (2x + 3)° = 180°
9x = 180
x = 20
Part C
m∠ADB = (3x - 5)°
= (3×20 - 5)°
= 55°
m∠DBK = (4x + 2)°
= (4×20 + 2)°
= 82°
m∠KBC = (2x + 3)°
= (2×20 + 3)°
= 43°
So it's best in this case to separate both shapes so you have a rectangle and a triangle so to solve the area of a rectangle you do
The following ( picture )
So I hope this helps
Approximately 1.143 L of peroxide should be added to the original solution.