Maths problem involving Coordimate Geometry

  • Thread starter Sanosuke Sagara
  • Start date
  • Tags
    Geometry
In summary, the equation of a straight line with x-intercept a and y-intercept b is given by the condition \frac{1}{a^2} + \frac{1}{b^2} = \frac{1}{c^2}. The locus of the foot of the perpendicular from the origin to this line is the curve X^2 + Y^2 = C^2, where c is a constant. This refers to the path traced by the intersection point of the line and the perpendicular as a and b vary.
  • #1
Sanosuke Sagara
102
0
find the equation of a straight line whose x-intercept and y-intercept are a and b respectively.If this line varies such that [tex]\frac{1}{a^2}[/tex] + [tex]\frac{1}{b^2}[/tex] = [tex]\frac{1}{c^2} [/tex]with c as a constant,show that the locus of the foot of the perpendicular from the origin to this line is the curve
[tex] X^2[/tex] +[tex] Y^2[/tex] = [tex]C^2 [/tex].


I want to ask what is meant by the phrase 'foot of the perpendicular from the origin to this line ' ?

I hope that somebody will help me to explain the meaning and thanks for anybody that spend some time on this question.
 
Last edited:
Mathematics news on Phys.org
  • #2
The 'foot of the perpendicular from the origin to this line' means the curve which the intesection of the line and the perpendicular forms as [tex]a[/tex] and [tex]b[/tex] are varied. This intersection point changes with [tex]a[/tex] and [tex]b[/tex], and the path that it traces they move through all their possible values is what the question is looking for.
 
  • #3


The phrase "foot of the perpendicular from the origin to this line" refers to the point where a line intersects with a perpendicular line drawn from the origin (point (0,0)) to the line. In this problem, we are looking at the locus (or path) of all these points for the given line.

To solve this problem, we first need to find the equation of the line with x-intercept a and y-intercept b. We know that the x-intercept is a, so it must pass through the point (a,0). Similarly, the y-intercept is b, so the line must also pass through the point (0,b). Using the slope-intercept form of a line, we can write the equation as:

y = (-b/a)x + b

Next, we are given that \frac{1}{a^2} + \frac{1}{b^2} = \frac{1}{c^2}, where c is a constant. We can rewrite this equation as:

\frac{1}{a^2} + \frac{1}{b^2} - \frac{1}{c^2} = 0

Multiplying both sides by (ab)^2, we get:

b^2 + a^2 - (ab)^2 = 0

This equation can be factored as:

(b - ac)(a - bc) = 0

Since c is a constant, we can write this as:

b = ac or a = bc

Substituting these values into the equation for our line, we get two possible equations:

y = (-b/ac)x + b or y = (-a/bc)x + b

Simplifying these equations, we get:

y = (-1/c)x + b or y = (-1/c)x + a

These two equations represent the same line, just in different forms. Now, we need to find the locus of the foot of the perpendicular from the origin to this line. To do this, we can use the distance formula to find the distance from the origin to any point on the line. The distance formula is:

d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}

Since the origin is at (0,0), the distance formula simplifies to:

d = \sqrt{x^2 + y^2}

Substituting the equations for
 

1. What is Coordinate Geometry?

Coordinate geometry is a branch of mathematics that deals with the study of geometric shapes in a coordinate plane. It involves using the coordinates of points to analyze and solve geometric problems.

2. What are the basic principles of Coordinate Geometry?

The basic principles of coordinate geometry include the use of a coordinate plane, Cartesian coordinates, equations of lines and curves, and the distance and midpoint formulas.

3. How do you plot points in a coordinate plane?

To plot points in a coordinate plane, you need to have the x-coordinate and y-coordinate of the point. The x-coordinate represents the horizontal position and the y-coordinate represents the vertical position. The point is then plotted by moving along the x-axis and then the y-axis to the respective coordinates.

4. How do you find the distance between two points in a coordinate plane?

The distance between two points in a coordinate plane can be found using the distance formula, which is: d = √((x2-x1)^2 + (y2-y1)^2). This formula finds the distance between any two points (x1, y1) and (x2, y2) in the coordinate plane.

5. What are some real-life applications of Coordinate Geometry?

Coordinate geometry has numerous real-life applications, such as in navigation systems, map-making, computer graphics, and engineering. It is also used in physics and astronomy to describe the positions and movements of objects in space.

Similar threads

Replies
2
Views
300
  • General Math
Replies
20
Views
1K
  • Precalculus Mathematics Homework Help
Replies
6
Views
418
  • General Math
Replies
4
Views
818
  • General Math
Replies
4
Views
1K
  • Precalculus Mathematics Homework Help
Replies
2
Views
997
  • Precalculus Mathematics Homework Help
Replies
3
Views
1K
  • General Math
Replies
1
Views
5K
  • General Math
Replies
4
Views
11K
  • General Math
Replies
1
Views
10K
Back
Top