345,180 views
43 votes
43 votes
Find the distance from a point (4, 6) to the line y = 2x - 5.

User Meberhard
by
2.5k points

1 Answer

10 votes
10 votes

Answer:

1.34 units.

Explanation:

The line y = 2x - 5 has a slope of 2 so the line passing through the given point will be perpendicular to y= 2x - 5 and will have a slope of -1/2.

Let this line be y = -1/2x + c.

Its passes through (4, 6) so:

6 = -1/2*4 + c

6 = -2 + c

c = 6 + 2 = 8

So, equation of this line is y = -1/2x + 8.

Now we find the point where the 2 lines intersect:

y = 2x - 5

y = -1/2x + 8

2x - 5 = -1/2x + 8

2x + 1/2 x = 5 + 8

(5/2)x = 13

x = 26/5

= 5.2.

and y = 2(5.2) - 5

= 5.4.

So, the point of intersection is (5.2, 5.4)

and the distance between the point (4,6) and the line y = 2x - 5

= √((6 - 5.4)^2 + (4-5.2)^2)

= √(0.36 + 1.44)

= √1.8

= 1.34

There is a formula you can use directly to solve this.

User Rene
by
2.4k points