Find x if the distance between the points x, 2 and 3, 4 is root 8 units
Answers
The value of x for point A is x = 3 + 2√15 or x = 3 - 2√15
Given: points A(x, 2) and B(3, 4).
The distance between points A and B is 8 units
To Find: The abscissa or x-coordinate of point A
Solution:
We can find the solution by applying the formula,
AB² = ( x2 - x1 )² + ( y2 - y1 )²
where ( x1 , y1 ) are coordinates of first point and ( x2 , y2 ) are coordinates of second point.
Framing our question where A(x, 2) and B(3, 4) and AB=8 units according to (1), we get
⇒ 8² = ( 3 - x )² + ( 4 - 2 )²
⇒ ( 3 - x )² = 60
⇒ 9 + x² - 6x - 60 = 0
⇒ x² - 6x - 51 = 0
The equation (1) cannot be prime factorised so we use Sridhar Acharya formula here which states,
x = ( - b ± √ ( b² - 4ac )) / 2a
∴ x = ( 6 ± √( 36 + 204 )) / 2
⇒ x = ( 6 ± 4√15) / 2
⇒ x = (3 ± 2√15)
So x = 3 + 2√15 or x = 3 - 2√15
Hence, the value of x for point A is x = 3 + 2√15 or x = 3 - 2√15
#SPJ3