Math Problem Statement

Find the point on the y-axis equidistant from the points (2, 3) and (-1, 2).

Solution

To find the point on the y-axis that is equidistant from the points (2,3)(2, 3) and (1,2)(-1, 2), follow these steps:

Step 1: Use the distance formula

The distance between two points (x1,y1)(x_1, y_1) and (x2,y2)(x_2, y_2) is given by:

d=(x2x1)2+(y2y1)2d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2}

Let the point on the y-axis be (0,y)(0, y), since any point on the y-axis has an xx-coordinate of 0. The distance from (0,y)(0, y) to (2,3)(2, 3) is:

d1=(20)2+(3y)2=4+(3y)2d_1 = \sqrt{(2 - 0)^2 + (3 - y)^2} = \sqrt{4 + (3 - y)^2}

The distance from (0,y)(0, y) to (1,2)(-1, 2) is:

d2=(10)2+(2y)2=1+(2y)2d_2 = \sqrt{(-1 - 0)^2 + (2 - y)^2} = \sqrt{1 + (2 - y)^2}

Step 2: Set the distances equal

Since the point on the y-axis is equidistant from both points, set d1=d2d_1 = d_2:

4+(3y)2=1+(2y)2\sqrt{4 + (3 - y)^2} = \sqrt{1 + (2 - y)^2}

Step 3: Square both sides

Square both sides to eliminate the square roots:

4+(3y)2=1+(2y)24 + (3 - y)^2 = 1 + (2 - y)^2

Step 4: Expand both sides

First, expand the squared terms:

(3y)2=96y+y2(3 - y)^2 = 9 - 6y + y^2 (2y)2=44y+y2(2 - y)^2 = 4 - 4y + y^2

Now substitute these into the equation:

4+96y+y2=1+44y+y24 + 9 - 6y + y^2 = 1 + 4 - 4y + y^2

Step 5: Simplify the equation

Combine like terms:

136y+y2=54y+y213 - 6y + y^2 = 5 - 4y + y^2

Now cancel the y2y^2 terms from both sides:

136y=54y13 - 6y = 5 - 4y

Step 6: Solve for yy

Move terms involving yy to one side and constants to the other side:

135=4y+6y13 - 5 = -4y + 6y 8=2y8 = 2y y=4y = 4

Final Answer:

The point on the y-axis that is equidistant from (2,3)(2, 3) and (1,2)(-1, 2) is (0,4)(0, 4).


Would you like more details on any part of the solution? Feel free to ask!

Here are some related questions you might find interesting:

  1. How would the solution change if the point was on the x-axis instead of the y-axis?
  2. How can you generalize this method for points not on the axes?
  3. Can we apply this method to points in three-dimensional space?
  4. How do you calculate the midpoint of two points geometrically?
  5. What is the relationship between the distance formula and the Pythagorean theorem?

Tip: When solving distance-related problems, always be mindful of the distance formula and the geometry of the problem—especially how symmetry (like being equidistant) can simplify the algebra.

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Math Problem Analysis

Mathematical Concepts

Coordinate Geometry
Distance Formula
Symmetry

Formulas

Distance Formula: d = sqrt((x2 - x1)^2 + (y2 - y1)^2)

Theorems

Equidistant Points
Properties of the Y-Axis

Suitable Grade Level

Grades 9-11