This is an ellipse.
Equation of an ellipse:
Let's find the center point first. We can do this by finding out the midpoint between the vertices or the foci.
(-9+7)/2=-1
Center: (-1,3)
Now we need to find a and b (length along x and length along y).
We know "a". It is the distance between the center and the right or left bound.
a=7-(-1)=8
To find out "b", first see that...
b^2=a^2-(distance from center to foci)^2
foci distance=3-(-1)=4
b^2=8^2-4^2
b^2=64-16
b^2=48
b=4√3
answer:
Answer:
Circumference of the smaller circle = 2.1x units
Step-by-step explanation:
Given question is incomplete; here is the complete question.
Two similar circles are shown. The circumference of the larger circle, with radius OB, is 3 times the circumference of the smaller circle, with radius OA. Radius OB measures x units. Which expression represents the circumference of the smaller circle with radius OA ?
Radius of the larger circle OB = x units
Radius of the smaller circle OA = y units
Circumference of larger circle = 2πx units
Circumference of smaller circle = 2πy units
Since circumference of larger circle is 3 times the circumference of smaller circle,
2πx = 3(2πy)
2πx = 6πy
x = 3y
y =
Therefore, circumference of the smaller circle = units
= units
= 2.094x
≈ 2.1x
Circumference of the smaller circle circle = 2.1x units