Answer:
C
Step-by-step explanation:
The equation is in the standard form for a circle:
(x-h)^2+(y-k)^2=r^2
where (h,k) is the center, and r is the radius
If we compare the 2 equations:
(x-h)^2+(y-k)^2=r^2
(x + 10)2 + (y + 9)2 = 100
We can see that r^2 is equal to 100. Let's set them equal to each other.
r^2=100
Since r is being squared, take the square root of both sides. This will cancel out the exponent.
r=10
So, our radius is 10, or choice C
Answer:
Part A:
1 book -- $7.25
9 books -- (9 * 7.25) = $65.25
And shipping fee -- (65.25 + 6.75) = $ 72
Part B
9 multiplied by the cost and added with the shipping fee to get Hannah's total cost.
Thenks and mark me brainliest :))
The one you answered is correct. It is infinitely steep
Answer:
The particle changes its direction 2 times within the time -3<t<3
Step-by-step explanation:
The particle is moving only in a single dimension (x-axis), and whenever the particle changes its direction it also means that it's velocity while changing the direction will be zero.
Hence,
v(t) = 0
but since we're not concerned with the actual values of t when v(t)=0, we'll only consider how many times does the particle changes its direction.
for that we'll simply plot the curve using half-steps from -3 to 3.
t, v(t)
-3, 115
-2.5, 23.9375
-2, -16
-1.5, -25.0625
-1, -19
-0.5, -9.0625
0, -2
0.5, -0.0625
1, -1
1.5, 1.9375
2, 20
2.5, 68.9375
3, 169
What we need to check is at what points does the sign of v(t) values change (because only between those points will v(t) cross the x-axis, hence it's value would've crossed 0)
so there are two points!
between the intervals t = [-2.5,2] and [1,1.5]
so there are two points where the particle changes its directions and those points lie somewhere between these two aforementioned intervals.
