Find the value of a when the distance between the points (3,a)and(4,1) is root10
Answers
Answer:
Step-by-step explanation:
Let the given points are A( 3 , a ) and B ( 4, 1 ).
Then,
X1 = 3 , X2 = 4 and Y1 = a , Y2 = 1
We have :
AB = √10 => AB² = (√10)²
=> AB² = 10
=> ( 4 - 3 )² + ( 1 - a )² = 10
=> (1)² + (1 - a )² = 10
=> ( 1 - a )² = 10 - 1
=> ( 1 - a )² = 9
=> ( 1 - a )² = (3)²
=> 1 - a = +- 3
=> 1 - a = 3 or 1 - a = -3
=> -a = 3 - 1 or -a = -3 - 1
=> -a = 2 or -a = -4
=> a = -2 or a = 4.
Given:-
- The distance between the points (3,a)and(4,1) is root10.
To find:-
- Find the value of a..?
Solutions:-
The distance d between two point (x1, y1) and (x2, y2) is given by the formula.
- d = √(x1 - x2)² + (y1 - y²)²
The distance between two points (3, a) and (4, 1) is given as √10
=> √10 = √(3 - 4)² + (a - 1)²
=> √10 = √( - 1)² + (a - 1)²
Now, Squaring the above equation on both sides of the equals sign.
=> 10 = (-1)² + (a - 1)²
=> 10 = 1 + (a² + 1 - 2a)
=> 10 = 1 + a² + 1 - 2a
=> 10 = 2 + a² - 2a
=> 10 - 2 = a² - 2a
=> 8 = a² - 2a
Thus, we arrive at a quadratic equation.
=> a² - 2a - 8 = 0
=> a² - 4a + 2a - 8 = 0
=> a(a - 4) + 2(a - 4) = 0
=> (a - 4) (a + 2) = 0