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Grade 12Analytical Geometry

an ellipse whose major axis is parallel to x- axis is such that the segmengts of focal chord are 1 and 3 units

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5 Years agoGrade 12
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1 Answer

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ApprovedApproved Tutor Answer1 Year ago

To understand the properties of the ellipse you're describing, let's break down the information step by step. An ellipse with its major axis parallel to the x-axis can be represented by the standard equation:

The Standard Form of an Ellipse

The equation for an ellipse centered at the origin with the major axis along the x-axis is:

(x²/a²) + (y²/b²) = 1

Here, 'a' represents the semi-major axis, and 'b' represents the semi-minor axis. The distance from the center to each focus is given by the formula:

c = √(a² - b²)

where 'c' is the distance from the center to each focus of the ellipse.

Understanding Focal Chords

A focal chord is a line segment that passes through one of the foci of the ellipse and has its endpoints on the ellipse itself. The lengths of the segments of a focal chord can provide valuable information about the ellipse's dimensions.

Given Information

You mentioned that the segments of the focal chord are 1 unit and 3 units. This means that if we denote the lengths of the segments from the focus to the points on the ellipse as 'p' and 'q', we have:

  • p = 1 unit
  • q = 3 units

The total length of the focal chord is then:

p + q = 1 + 3 = 4 units

Using the Properties of Ellipses

For any ellipse, the product of the lengths of the segments of a focal chord is equal to the square of the semi-minor axis:

p * q = b²

Substituting the values we have:

1 * 3 = b²

Thus, we find:

b² = 3

From this, we can determine that:

b = √3

Finding the Semi-Major Axis

Now, we need to find the semi-major axis 'a'. We know that the total length of the focal chord is also related to the semi-major axis. The relationship is given by:

p + q = 2a

Substituting the known values:

4 = 2a

From this, we can solve for 'a':

a = 2

Calculating the Distance to the Foci

Now that we have both 'a' and 'b', we can find 'c', the distance from the center to the foci:

c = √(a² - b²)

Substituting the values we found:

c = √(2² - (√3)²)

c = √(4 - 3) = √1 = 1

Final Equation of the Ellipse

Now that we have all the necessary values, we can write the equation of the ellipse:

(x²/2²) + (y²/(√3)²) = 1

This simplifies to:

(x²/4) + (y²/3) = 1

In summary, the ellipse you described has a semi-major axis of 2 units and a semi-minor axis of √3 units, with the equation:

(x²/4) + (y²/3) = 1