The endpoints of [tex]\(\overline{CD}\)[/tex] are [tex]\(C(-8, 4)\)[/tex] and [tex]\(D(6, -6)\)[/tex]. What are the coordinates of point [tex]\(P\)[/tex] on [tex]\(\overline{CD}\)[/tex] such that [tex]\(P\)[/tex] is [tex]\(\frac{5}{8}\)[/tex] the length of the line segment from [tex]\(D\)[/tex]?

A. [tex]\((-2.75, 0.25)\)[/tex]
B. [tex]\((-5, 2.5)\)[/tex]
C. [tex]\((0.75, -2.25)\)[/tex]
D. [tex]\((3.75, -3.75)\)[/tex]



Answer :

To find the coordinates of point [tex]\( P \)[/tex] on the line segment [tex]\(\overline{CD}\)[/tex] such that the point [tex]\( P \)[/tex] divides the segment from [tex]\(D\)[/tex] in the ratio [tex]\(\frac{5}{8}\)[/tex], we can use the section formula in coordinate geometry. This formula helps us determine the coordinates of a point that divides a line segment joining two points in a given ratio.

Given:
- Coordinates of [tex]\(C = (-8, 4)\)[/tex]
- Coordinates of [tex]\(D = (6, -6)\)[/tex]
- Ratio in which [tex]\(P\)[/tex] divides the segment from [tex]\(D\)[/tex] is [tex]\( \frac{5}{8} \)[/tex]

We use the section formula:
[tex]\[ P = \left( \frac{mx_2 + nx_1}{m+n}, \frac{my_2 + ny_1}{m+n} \right) \][/tex]
where
- [tex]\((x_1, y_1)\)[/tex] are the coordinates of [tex]\(C\)[/tex]
- [tex]\((x_2, y_2)\)[/tex] are the coordinates of [tex]\(D\)[/tex]
- [tex]\(m\)[/tex] and [tex]\(n\)[/tex] are the parts into which the line segment is divided

Here, the section formula will be adapted because the problem specifies the point [tex]\(P\)[/tex] to be [tex]\( \frac{5}{8} \)[/tex] of the length from [tex]\( D \)[/tex]. This implies [tex]\(m = 5\)[/tex] and [tex]\( n = 3\)[/tex] because:

[tex]\[ \frac{m}{m+n} = \frac{5}{8} \][/tex]

Now, substituting [tex]\(m = 5\)[/tex] and [tex]\(n = 3\)[/tex] into the coordinates:

1. Compute the x-coordinate of [tex]\(P\)[/tex]:

[tex]\[ p_x = \frac{5 \cdot (-8) + 3 \cdot 6}{5 + 3} = \frac{(-40) + 18}{8} = \frac{-22}{8} = -2.75 \][/tex]

2. Compute the y-coordinate of [tex]\(P\)[/tex]:

[tex]\[ p_y = \frac{5 \cdot 4 + 3 \cdot (-6)}{8} = \frac{20 + (-18)}{8} = \frac{2}{8} = 0.25 \][/tex]

Therefore, the coordinates of point [tex]\(P\)[/tex] are [tex]\((-2.75, 0.25)\)[/tex].

Thus, the correct answer is:
- [tex]\((-2.75, 0.25)\)[/tex]

This matches the point we computed!

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