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Example Questions
Example Question #31 : Hyperbolas And Ellipses
Find the eccentricity of the ellipse with the following equation:
Start by putting this equation in the standard form of the equation of an ellipse:
, where is the center of the ellipse.
Group the terms together and the terms together.
Factor out from the terms and from the terms.
Now, complete the squares. Remember to add the same amount to both sides!
Subtract from both sides.
Divide both sides by .
Factor both terms to get the standard form of the equation of an ellipse.
Recall that the eccentricity is a measure of the roundness of an ellipse. Use the following formula to find the eccentricity, .
Next, find the distance from the center to the focus of the ellipse, . Recall that when , the major axis will lie along the -axis and be horizontal and that when , the major axis will lie along the -axis and be vertical.
is calculated using the following formula:
for , or
for
For the ellipse in question,
Now that we have found the distance from the center to the foci, we need to find the distance from the center to the vertex.
Because , the major axis for this ellipse is horizontal. will be the distance from the center to the vertices.
For this ellipse, .
Now, plug in the distance from the center to the focus and the distance from the center to the vertex to find the eccentricity of this ellipse.
Example Question #124 : Conic Sections
Find the eccentricity of the ellipse with the following equation:
Start by putting this equation in the standard form of the equation of an ellipse:
, where is the center of the ellipse.
Group the terms together and the terms together.
Factor out from the terms and from the terms.
Now, complete the squares. Remember to add the same amount to both sides!
Add to both sides.
Divide both sides by .
Factor both terms to get the standard form of the equation of an ellipse.
Recall that the eccentricity is a measure of the roundness of an ellipse. Use the following formula to find the eccentricity, .
Next, find the distance from the center to the focus of the ellipse, . Recall that when , the major axis will lie along the -axis and be horizontal and that when , the major axis will lie along the -axis and be vertical.
is calculated using the following formula:
for , or
for
For the ellipse in question,
Now that we have found the distance from the center to the foci, we need to find the distance from the center to the vertex.
Because , the major axis for this ellipse is horizontal. will be the distance from the center to the vertices.
For this ellipse, .
Now, plug in the distance from the center to the focus and the distance from the center to the vertex to find the eccentricity of this ellipse.
Example Question #32 : Hyperbolas And Ellipses
Find the eccentricity of the ellipse with the following equation:
Recall that the eccentricity is a measure of the roundness of an ellipse. Use the following formula to find the eccentricity, .
Next, find the distance from the center to the focus of the ellipse, . Recall that when , the major axis will lie along the -axis and be horizontal and that when , the major axis will lie along the -axis and be vertical.
is calculated using the following formula:
for , or
for
For the ellipse in question,
Now that we have found the distance from the center to the foci, we need to find the distance from the center to the vertex.
Because , the major axis for this ellipse is vertical. will be the distance from the center to the vertices.
For this ellipse, .
Now, plug in the distance from the center to the focus and the distance from the center to the vertex to find the eccentricity of this ellipse.
Example Question #126 : Conic Sections
Find the eccentricity of the ellipse with the following equation:
Recall that the eccentricity is a measure of the roundness of an ellipse. Use the following formula to find the eccentricity, .
Next, find the distance from the center to the focus of the ellipse, . Recall that when , the major axis will lie along the -axis and be horizontal and that when , the major axis will lie along the -axis and be vertical.
is calculated using the following formula:
for , or
for
For the ellipse in question,
Now that we have found the distance from the center to the foci, we need to find the distance from the center to the vertex.
Because , the major axis for this ellipse is vertical. will be the distance from the center to the vertices.
For this ellipse, .
Now, plug in the distance from the center to the focus and the distance from the center to the vertex to find the eccentricity of this ellipse.
Example Question #33 : Hyperbolas And Ellipses
Find the eccentricity of the ellipse
.
To find the eccentrictity, first we need to find c, the distance from the center to the foci. We can use the equation where a and b are the lengths of half the minor and major axes, and c is the distance from the center to the foci.
The eccentricity is where c is half the length of the major axis. In this case, because 49 is greater than 25.
The eccentricity is .
Example Question #34 : Hyperbolas And Ellipses
Find the eccentricity of
To find the eccentricity, first find "c" as we would if we were finding the focus. The relationship between a, the radius of the major axis, b, the radius of the minor axis, and c for an ellipse is:
add c squared to both sides
subtract 4 from both sides
take the square root
Since , .
The eccentricity is so here
Example Question #31 : Hyperbolas And Ellipses
Find the eccentricity of
First find "c" by using the relationship where a is the radius of the major axis and b is the radius of the minor axis.
add c squared to both sides
subtract 2 from both sides
take the square root of both sides
The eccentricity is . Since ,
Example Question #31 : Hyperbolas And Ellipses
The equation of an ellipse is given by
Find the eccentricity of the ellipse.
The equation for the eccentricity of an ellipse is given by
where c is the distance from the center to the foci and a is the square root of the larger denominator. To find c, use the equation , where is the larger denominator and is the smaller denominator. Plugging in the values, we have
Plugging the values into the equation gives
Example Question #31 : Hyperbolas And Ellipses
Find the endpoints of the major and minor axes of the ellipse described by the following equation:
In order to find the endpoints of the major and minor axes of our ellipse, we must first remember what each part of the equation in standard form means:
The point given by (h,k) is the center of our ellipse, so we know the center of the ellipse in the problem is (8,-2), and we know that the end points of our major and minor axes will line up with the center either in the x or y direction, depending on the axis. The parts of the equation that will tell us the distance from the center to the endpoints of each axis are and . If we take the square root of each, a will give us the distance from the center to the endpoints in the positive and negative x direction, and b will give us the distance from the center to the endpoints in the positive and negative y direction:
Now it is important to consider the definition of major and minor axes. The major axis of an ellipse is the longer one, will the minor axis is the shorter one. We can see that b=5, which means the axis is longer in the y direction, so this is the major axis. To find the endpoints of the major axis, we'll go 5 units from the center in the positive and negative y direction, respectively, giving us:
Similarly, to find the endpoints of the minor axis, we'll go 2 units from the center in the positive and negative x direction, respectively, giving us:
Example Question #31 : Understand Features Of Hyperbolas And Ellipses
The equation of an ellipse, , is . Which of the following are the correct end points of the MAJOR axis of this ellipse?
and
and
and
and
and
and
First, we must determine if the major axis is a vertical axis or a horizontal axis. We look at our denominators, and , and see that the larger one is under the -term. Therefore, we know that the greater axis will be a vertical one.
To find out how far the end point are from the center, we simply take . So we know the end points will be units above and below our center. To find the center, we must remember that for ,
the center will be .
So for our equation, the center will be . units above and below the center give us and .
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