Method 2: Trigonometry

Using this method, we will first construct a right triangle by drawing a horizontal and vertical line to y=2x+4 from the point (4, 1). Knowing the length of these sides, we'll then find angle Θ using the big triangle, and then use Θ to solve for d in the lower small triangle.

Step 1: Draw the Lines

Draw a horizontal line from (4, 1) to the line y=2x+4.
It meets the line at a point with y coordinate 1.
Substituting y=1 in the line equation y=2x+4 yields the value of -1.5 for x.
So the left corner of the triangle is (-1.5, 1).

Draw a vertical line from (4, 1) to the line y=2x+4.
It meets the line at a point whose x coordinate must be 4.
Substituting x=4 in the line equation y=2x+4 yields the value of 12 for y.
So the top corner of the triangle is (4, 12).

Step 2: Find Θ

Given where angle Θ is, we now know that:
  - the opposite side of the large triangle has length 11
  - the adjacent side has length 5.5.

      

Step 3: Find d:

Using the small triangle, we know an angle, and the hypotenuse 5.5


Method 2 gives an answer of 4.92 for the distance from point (4, 1) to line y=2x+4


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