Assuming the area below the line y=0 (i.e. x>1) does NOT count, the area to be rotated is shown in the graph attached.
A. Again, using Pappus's theorem,
Area, A = (2/3)*1*(1-(-1))=4/3 (2/3 of the enclosing rectangle, or you can integrate)
Distance of centroid from axis of rotation, R = (2-0) = 2
Volume = 2 π RA = 2 π 2 * 4/3 = 16 π / 3 (approximately = 16.76 units)
B. By integration, using the washer method
Volume =
![=2\pi[x^4/4-2x^3/3-x^2/2+2x]_{-1}^{1}](https://tex.z-dn.net/?f=%3D2%5Cpi%5Bx%5E4%2F4-2x%5E3%2F3-x%5E2%2F2%2B2x%5D_%7B-1%7D%5E%7B1%7D)
![=2\pi([1/4-2/3-1/2+2]-[1/4+2/3-1/2-2])](https://tex.z-dn.net/?f=%3D2%5Cpi%28%5B1%2F4-2%2F3-1%2F2%2B2%5D-%5B1%2F4%2B2%2F3-1%2F2-2%5D%29)
= 16 π /3 as before
Answer:
21+10.5 which would equal 31.5
Step-by-step explanation:
Hey there!
We are looking for the circumference of the circle, which is the distance around it. We are given the area, which is the radius squared times pi.
First, we need to undo the area to find our radius.
113.04/3.14=36
We square root this to find the radius.
√36=6
Our radius is six. To find the circumference, we need to multiply the diameter by pi. The diameter is twice the radius.
6*2=12
12*3.14=37.68
Therefore, we will need 37.68 feet of trim to around the edge of the quilt.
I hope this helps!
We know that
speed=distance/time
solve for time
time=distance/speed
in this problem
<span>Marco runs at a rate of 6 miles per hour.
</span><span>Fernando funs at a rate of 7.2 miles per hour
Difference=7.2-6=1.2 miles/hour
so
speed=1.2 miles/hour
distance=0.3 miles
time=?
</span>time=distance/speed-----> 0.3/1.2-----> 0.25 hour-----> 0.25*60=15 minutes
<span>
the answer is
0.25 hour (15 minutes)
Alternative Method
Let
x---------> Fernando's distance when Marco is 0.3 miles apart
</span>Fernando funs at a rate of 7.2 miles per hour
<span>for distance =x
time=x/7.2------> equation 1
</span>Marco runs at a rate of 6 miles per hour.
for distance=x-0.30
time=(x-0.30)/6------> equation 2
equate equation 1 and equation 2
7.2*(x-0.3)=6x-----> 7.2x-2.16=6x
7.2x-6x=2.16------> x=2.16/1.2-------> x=1.8 miles
time=x/7.2-----1.8/7.2=0.25 hour
Answer:
12 = 22 × 3
Step-by-step explanation:
