Consider line A which is defined by the equation:
y=5/6x-5/2
and the point P(-3,6) and then answer the following questions:
a. How would you find the line (B) that passes through point P and is perpendicular to line A? What is the equation of that line?
b. How would you find the length of the segment of line B from point P to line A?
c. How would you find the midpoint between point P and the intersection of line A and line B ?

Respuesta :

Answer:

  • y = -6/5x +12/5
  • distance from P to A: (66√61)/61 ≈ 8.4504
  • midpoint: (-18/61, 168/61) ≈ (-0.2951, 2.7541)

Step-by-step explanation:

a. The slope of the perpendicular line is the negative reciprocal of the slope of the given line, so is ...

  m = -1/(5/6) = -6/5

Then the point-slope form of the desired line through (-3, 6) can be written as ...

  y = m(x -h) +k . . . . . line with slope m through (h, k)

  y = (-6/5)(x +3) +6

  y = -6/5x +12/5 . . . equation of line B

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b. The distance from point P to the intersection point (X) can be found from the formula for the distance from a point to a line.

When the line's equation is written in general form, ax+by+c=0, the distance from point (x, y) to the line is ...

  d = |ax +by +c|/√(a² +b²)

The equation of line A can be written in general form as ...

  y = 5/6x -5/2

  6y = 5x -15

  5x -6y -15 = 0

Then the distance from P to the line is ...

  d = |5(-3) -6(6) -15|/√(5² +(-6)²) = 66/√61

The length of segment PX is (66√61)/61.

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c. To find the midpoint, we need to know the point of intersection, X. We find that by solving the simultaneous equations ...

  y = 5/6x -5/2

  y = -6/5x +12/5

Equating y-values gives ...

  5/6x -5/2 = -6/5x +12/5

Adding 6/5x +5/2 gives ...

  x(5/6+6/5) = 12/5 +5/2

  x(61/30) = 49/10

  x = (49/10)(30/61) = 147/61

  y = 5/6(147/61) -5/2 = -30/61

Then the point of intersection of the lines is X = (147/61, -30/61).

So, the midpoint of PX is ...

  M = (P +X)/2

  M = ((-3, 6) +(147/61, -30/61))/2

  M = (-18/61, 168/61)

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