Question

The points k(-3,2) and L(3,j) are 9 units apart find j. How do I do this with simple explanation, I’m a beginner

Answer 1

`j =2 \pm 3 √(5)`

Explanation:

Use the distance formula:

`d= \sqrt{(x_(1) - x_(2))^(2) - (y_(1) - y_(2))^(2) }`

Since the two points k(-3,2) and L(3,j) are 9 units apart find j, we substitute d=9 and the coordinates to get:

`9 = \sqrt{( {3 - - 3)}^(2) + (j - 2) ^(2) }`

`9 = \sqrt{ {6}^(2) + {(j - 2)}^(2) }`

`81 = 36 + {(j - 2)}^(2)`

`81 - 36 = {(j - 2)}^(2)`

`45 = {(j - 2)}^(2)`

Take square root of both sides:

`j= 2 \pm3 √(5)`