Answer:
Step-by-step explanation:
The formula of a circumference of a circle:
r - radius
We have <em>r = 8</em>. Substitute:
Option D is the correct answer
Answer:
10 gallons
Step-by-step explanation:
Amy's car's maximum capacity to hold gas = 19 gallons
present amount of gas = 9 gallons
As the car's capacity is 19 gallons and present amount in tank is 9 gallons, so we can fill it as much as so that the amount in tank becomes 19 gallons.
let assume she fills x gallons
then x gallons and 9 gallons present earlier should be equal to 19 gallon, as the tank can not hold more than that.
lets write it mathematically
x + 9 = 19
subtracting 9 from both side
x + 9 - 9 = 19 - 9
=> x = 10
Thus, 10 gallons of gas is needed to fill the gas tank.
You have to complete the squares on both the x terms and the y terms in order to solve this. Move the 20 over to the other side so it's negative. Group the x terms together and complete the square to get (x^2+2x+1) and then do the same with the y terms: (y^2-4y+4). You have to add 1 and 4 to other side with the 20 to get a 25. Then create 2 perfect square binomials within each x and y value to get the vertex coordinates: (x+1)^2 + (y-2)^2 = 25. This tells us that the vertex is located at (-1, 2) and the radius is the square root of 25 which is 5.So the answer is the first choice above.
ANSWER
The correct choice is A.
EXPLANATION
The given cosine function is:
This function has an amplitude of 2.
Hence it must have range,
-2≤f(t)≤2
It has a period of
Hence the function must complete one cycle on the interval,
[0,½π],
[½π,π],
etc.
The negative sign shows a reflection in the y-axis but since the cosine function is even, the function retraces itself.
The correct choice is A
