Answer:
The desired distance is √5
Step-by-step explanation:
Recall that the distance from a point to a line is measured along a path perpendicular to the line. Thus, given the line y = -2x + 5, the slope of any line perpendicular to it is the negative reciprocal of -2: +1/2.
The line perpendicular to y = -2x + 5 and passing through (4, 2) is
y - 2 = (1/2)(x - 4), or
2y - 4 = x - 4, or 2y = x, or y = (1/2)x.
Now our problem becomes "find the length of the line connecting (4, 2) and the intersection of y = -2x + 5 and y = (1/2)x."
Equating these, we get (1/2)x = -2x + 5, which, if multiplied through by 2, becomes x = -4x + 10, or 5x = 10, or x = 2. If x = 2, then y = (1/2)(2) = 1.
Finally, find the distance between (2, 1) and (4, 2):
Using the Pythagorean Theorem, d = √(2^2 + 1^2) = √5
The distance from (4, 2) to the line y = -2x + 5 is √5
