Answer:
k = -3 or 5
Step-by-step explanation:
The given parameters are;
The line extends from points (-1, 1) to point (2, k)
The length of the line = 5 units
The formula for the length, l, of a line given its coordinates can be found by the following formula;
Therefore, we have;
Which, by squaring both sides, gives;
25 = (k - 1)² + (2 - (-1))² = (k - 1)² + (2 + 1)² = (k - 1)² + 3²
25 = (k - 1)² + 3² = k² - 2·k + 1 + 9
25 - 25 = 0 = k² - 2·k + 1 + 9 - 25 = k² - 2·k - 15
0 = k² - 2·k - 15
0 = (k +3) × (k - 5)
Therefore, k = -3 or 5
When k - -3, we have;
When k = 5, we have;