The easiest way is to try the point (-4,1), that is, x=-4, y=1,
to see which equation works.
b works.
The usual way to do it is to find the equation of the circle
standard form of a circle is (x-h)²+(y-k)²=r², (h,k) are the coordinates of the center, r is the radius.
in this case, the center is (-2,1), so (x+2)²+(y-1)²=r²
the given point (-4,1) is for you to find r: (-4+2)²+(1-1)²=r², r=2
so the equation is (x+2)²+(y-1)²=2²
expand it: x²+4x+4+y²-2y+1=4
x²+y²+4x-2y+1=0, which is answer b.
Answer:
10 in
Step-by-step explanation:
There are two ways to work this problem, and they give different answers. The reason for that is that <em>the data shown in the diagram is not consistent</em>.
<u>Method 1</u>
Use the area to determine the base length. The area formula is ...
A = (1/2)bh
20 in^2 = (1/2)(b)(4 in)
(20 in^2)/(2 in) = b = 10 in
The missing side dimension is 10 inches.
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<u>Method 2</u>
Use the Pythagorean theorem to find the parts of the base, then add them up.
Left of the "?" we have ...
left^2 +4^ = 6^
left^2 = 36 -16 = 20
left = √20 = 2√5
Right of the "?" we have ...
right^2 +4^2 = 8^2
right^2 = 64 -16 = 48
right = √48 = 4√3
So, the base length is ...
base = left + right = 2√5 +4√3
base ≈ 11.400 in
The missing side dimension is 11.4 inches. (The area is 22.8 in^2.)
Answer:
(294π +448) cm³ ≈ 1371.6 cm³
Step-by-step explanation:
The half-cylinder at the right end has a radius of 7 cm, as does the one on top. Together, the total length of these half-cylinders is 8 cm + 4cm = 12 cm. That is equivalent in volume to a whole cylinder of radius 7 cm that is 6 cm long.
The cylinder volume is ...
V = πr²h = π(7 cm)²(6 cm) = 294π cm³
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The cuboid underlying the top half-cylinder has dimensions 4 cm by 8 cm by 14 cm (twice the radius). So, its volume is ...
V = LWH = (4 cm)(8 cm)(14 cm) = 448 cm³
Then the total volume of the composite figure is ...
(294π +448) cm³ ≈ 1371.6 cm³
Ok, you can refer to the midpoint formula to find the endpoint. Here goes...
MP=(2,-7) and EP=(8,-5)
Let x represent the missing endpoint.
(8+x)/2=2 NOTE: =2 represents first number of MP and the representation of number 8 is self explanatory. You have two endpoints but need to identify the other endpoint so you divide by 2. Then, multiply by two on both sides.
2(8+x)/2 = 2*2
16+x/2=4 do the next step (simplify) on the left side of equation 16x/2=8
Now, subtract 4-8=-4 So, the x coordinated of the missing endpoint is -4.
Volume of cylinder = πr²h = π x 4² x 6 = 96π
volume of cone = 1/3πR²H = 1/3π x 8² x 12 = 256π
You can see that volume of cone is more than twice of volume of cylinder. So she is not correct
