What is the y-coordinate of the point that divides the directed line segment from [tex]\( J \)[/tex] to [tex]\( K \)[/tex] into a ratio of [tex]\( 5:11 \)[/tex]?

A. [tex]\(-8\)[/tex]

B. [tex]\(-5\)[/tex]

C. [tex]\(0\)[/tex]

D. [tex]\(6\)[/tex]



Answer :

To find the [tex]$y$[/tex]-coordinate of the point that divides the directed line segment from [tex]$J$[/tex] to [tex]$K$[/tex] in the ratio of [tex]$5:11$[/tex], we'll use the section formula. Here is a step-by-step solution:

1. Identify the coordinates and the ratio:
- For point [tex]$J$[/tex], the [tex]$y$[/tex]-coordinate is [tex]\( y_J = -8 \)[/tex].
- For point [tex]$K$[/tex], the [tex]$y$[/tex]-coordinate is [tex]\( y_K = 6 \)[/tex].
- The given ratio is [tex]\( 5:11 \)[/tex], meaning [tex]\( m = 5 \)[/tex] and [tex]\( n = 11 \)[/tex].

2. Apply the section formula:
The section formula for finding the coordinate of a point dividing the line segment in the ratio [tex]\( m:n \)[/tex] is:
[tex]\[ v = \left( \frac{m}{m+n} \right) \left( v_2 - v_1 \right) + v_1 \][/tex]
Here, [tex]\( v_1 = y_J \)[/tex] and [tex]\( v_2 = y_K \)[/tex].

3. Substitute the values into the formula:
[tex]\[ y = \left( \frac{5}{5+11} \right) (6 - (-8)) + (-8) \][/tex]

4. Simplify the expression:
- Calculate the denominator: [tex]\( 5 + 11 = 16 \)[/tex].
- Calculate the numerator inside the parentheses: [tex]\( 6 - (-8) = 6 + 8 = 14 \)[/tex].

5. Substitute back into the formula:
[tex]\[ y = \left( \frac{5}{16} \right) \cdot 14 + (-8) \][/tex]

6. Perform the multiplication:
[tex]\[ y = \left( \frac{5 \cdot 14}{16} \right) + (-8) = \frac{70}{16} - 8 \][/tex]

7. Simplify the fraction:
[tex]\[ y = \frac{70}{16} = 4.375 \][/tex]

8. Complete the calculation:
[tex]\[ y = 4.375 - 8 = -3.625 \][/tex]

Thus, the [tex]\( y \)[/tex]-coordinate of the point dividing the directed line segment from [tex]\( J \)[/tex] to [tex]\( K \)[/tex] in the ratio [tex]\( 5:11 \)[/tex] is [tex]\(-3.625\)[/tex].

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