3. Find the point on the X - axis Which is equidistant from A (-3,4) and B (1,-4) .
Answers
Explanation:
the coordinates of point which is present on x axis is (x, 0)
let P(x, 0) is equidistant point from A(-3, 4) and B(1, -4)
PA=PB
squaring on both sides
PA^2=PB^2
[x-(-3) ]+(0-4) =(x-1) +[0-(-4) ]
x+3) +16=x^2-2x+1+16
x^2+6x+9+16=x^2-2x+1+16
6x+9=-2x+1
6x+2x=9-1
8x=8
x=8/8
x=1
Given points:-
- A(-3, 4) and B(1, -4)
To find:-
- The point on x - axis which is equidistant from these points.
Solution:-
Let the point on x - axis be C(x, 0)
The point on x - axis is equidistant to points A and B
Hence, we can write,
- AC = BC ⟶ (i)
Let us calculate the distance between AC and BC separately by using distance formula.
For AC,
A(-3, 4) and C(x, 0)
Here,
x₁ = -3 and x₂ = x
y₁ = 4 and y₂ = 0
We know,
- Distance formula = √(x₂ - x₁) + (y₂ - y₁)
Putting the values in the formula,
AC = √[x - (-3)]² + [0 - 4]²
AC = √ (x + 3)² + (-4)²
Using identity (a + b)² = a² + 2ab + b²
AC = √x² + 6x + 9 + 16
AC = √x² + 6x + 25
Now,
For BC
B(1, -4) and C(x, 0)
x₁ = 1 and x₂ = x
y₁ = -4 and y₂ = 0
Putting the values in the distance formula,
BC = √[x - 1]² + [0 - (-4)]²
Using the identity (a - b)² = a² - 2ab + b²
BC = √x² - 2x + 1 + (4)²
BC = √x² - 2x + 1 + 16
BC = √x² - 2x + 17
Now,
From (i) we have AC = BC
Hence,
√x² + 6x + 25 = √x² - 2x + 17
Squaring on both sides,
= (√x² + 6x + 25)² = (√x² - 2x + 17)
⇒ x² + 6x + 25 = x² - 2x + 17
Bringing x² from RHS to LHS,
= x² - x² + 6x + 25 = -2x + 17
⇒ 6x + 25 = -2x + 17
Bringing all the variables on LHS and Constant on RHS,
= 6x + 2x = -25 + 17
⇒ 8x = -8
⇒ x = -8/8
⇒ x = -1
∴ The point on x - axis which is equidistant to points A(-3, 4) and B(1, -4) is (-1, 0).
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