The distance of the point ( 7 , − 2 , 11 ) ( 7 , − 2 , 11 ) from the line along the line is :
Correct Answer :
14
Solution :
The correct answer is 14.
To find the distance of the point P(7, -2, 11) from the line:
measured along (or parallel to) the line:
we will find the equation of a line passing through P(7, -2, 11) parallel to
and determine its intersection point with
.
Step 1: Write the equation of the line passing through P and parallel to
The direction ratios of the line are (2, -3, 6). Since the new line is parallel to , it shares the same direction ratios.
Therefore, the equation of the line passing through P(7, -2, 11) in parametric form is:
Any general point Q on this line can be written in terms of as:
Step 2: Find the point of intersection of this line with
For Q to lie on the line , its coordinates must satisfy the equation of .
The equation of is:
Since the denominator of the y-term is 0, this implies that the y-coordinate is constant on this line:
Substituting the y-coordinate of Q:
Now, substitute back to find the coordinates of the intersection point Q:
So, the intersection point is Q(3, 4, -1).
Let us verify if Q(3, 4, -1) lies on :
Since and y = 4, Q lies on .
Step 3: Calculate the distance between P and Q
Using the distance formula:
Substitute the coordinates of P(7, -2, 11) and Q(3, 4, -1):
The distance is 14.
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