Math Problem Statement

Find the distance from the line y = (5/4)x - 4 to (-1, 5).

Solution

The problem asks to find the distance from the line y=54x4y = \frac{5}{4}x - 4 to the point (1,5)(-1, 5).

To find the distance from a point (x1,y1)(x_1, y_1) to a line given by Ax+By+C=0Ax + By + C = 0, we use the formula:

d=Ax1+By1+CA2+B2d = \frac{|Ax_1 + By_1 + C|}{\sqrt{A^2 + B^2}}

Step 1: Rearrange the line equation

The given equation y=54x4y = \frac{5}{4}x - 4 can be written in standard form: 54xy4=0\frac{5}{4}x - y - 4 = 0 Multiply through by 4 to clear the fraction: 5x4y16=05x - 4y - 16 = 0 Here, A=5A = 5, B=4B = -4, and C=16C = -16.

Step 2: Apply the distance formula

Substitute the coordinates of the point (1,5)(-1, 5) into the formula: d=5(1)+(4)(5)1652+(4)2d = \frac{|5(-1) + (-4)(5) - 16|}{\sqrt{5^2 + (-4)^2}}

Step 3: Simplify the numerator

d=5201625+16d = \frac{| -5 - 20 - 16 |}{\sqrt{25 + 16}} d=4141d = \frac{|-41|}{\sqrt{41}} d=4141d = \frac{41}{\sqrt{41}}

Step 4: Rationalize the denominator (if needed)

d=41d = \sqrt{41}

Final Answer:

The distance from the point (1,5)(-1, 5) to the line y=54x4y = \frac{5}{4}x - 4 is: 41\sqrt{41}

Would you like me to elaborate on any step?


5 Related Questions:

  1. How is the formula for the distance from a point to a line derived?
  2. What happens if the coordinates of the point were different (e.g., (0,0)(0, 0))?
  3. Can you verify this result geometrically or with a graph?
  4. What other methods can be used to compute the distance from a point to a line?
  5. How do we calculate distances if the line is given in parametric form?

Tip:

Always write the equation of the line in standard form Ax+By+C=0Ax + By + C = 0 before applying the distance formula.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Coordinate Geometry
Distance from Point to Line

Formulas

d = |Ax1 + By1 + C| / sqrt(A^2 + B^2)

Theorems

Perpendicular Distance Formula

Suitable Grade Level

Grades 9-12