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Question 6
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Given point A = (-19, -2) and point B = (3, -7). A point C divides the line joining AB in the
2:5, i.e point C is nearer to point A. What is the equation of the line perpendicular to line
passes through point C, in the form of y = mx + c?
Answer: (Correct to 3 decimal places) The equation of the line is y =

1 Answer

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Answer:

The equation of a line perpendicular to another line can be found using the following steps:

1. Find the slope of the line AB:

The slope (m) of a line passing through points A = (-19, -2) and B = (3, -7) can be calculated using the formula:

m = (y2 - y1) / (x2 - x1)

Plugging in the values, we get:

m = (-7 - (-2)) / (3 - (-19))

= (-7 + 2) / (3 + 19)

= -5 / 22

2. Find the negative reciprocal of the slope:

The negative reciprocal of the slope (-5/22) is obtained by flipping the fraction and changing the sign. So, the negative reciprocal is 22/5.

3. Use the slope-intercept form of the equation (y = mx + c):

We know that the line passes through point C, which divides the line AB in the ratio 2:5. Since point C is nearer to point A, we can assume that point C is 2/7 times the distance from point A to point B.

To find the coordinates of point C, we can use the following formula:

x-coordinate of C = (2 * x-coordinate of B + 5 * x-coordinate of A) / (2 + 5)

y-coordinate of C = (2 * y-coordinate of B + 5 * y-coordinate of A) / (2 + 5)

Plugging in the values, we get:

x-coordinate of C = (2 * 3 + 5 * (-19)) / (2 + 5)

= (6 - 95) / 7

= -89/7

y-coordinate of C = (2 * (-7) + 5 * (-2)) / (2 + 5)

= (-14 - 10) / 7

= -24/7

Now, we have the coordinates of point C, which are (-89/7, -24/7), and the negative reciprocal of the slope, which is 22/5.

Substituting these values into the slope-intercept form of the equation (y = mx + c), we get:

y = (22/5) * x + c

4. Find the value of c:

To find the value of c, we can substitute the coordinates of point C into the equation and solve for c. Using the coordinates (-89/7, -24/7), we get:

-24/7 = (22/5) * (-89/7) + c

Solving this equation, we find:

c = -24/7 - (22/5) * (-89/7)

= -24/7 + 22 * 89/35

= -24/7 + 1958/35

= -240/70 + 1958/35

= -240/70 + 1114/70

= 874/70

= 437/35

Therefore, the equation of the line perpendicular to line AB and passing through point C is:

y = (22/5) * x + 437/35

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