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Show that the line through the points (4, 7, 8) (2, 3, 4) is parallel to the line through the points (−1, −2, 1), (1, 2, 5).

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प्रश्न

Show that the line through the points (4, 7, 8) (2, 3, 4) is parallel to the line through the points (−1, −2, 1), (1, 2, 5).

योग
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उत्तर

Let A(4, 7, 8), B(2, 3, 4), C(−1, −2, 1), D(1, 2, 5)

Direction ratio of AB = (2 − 4, 3 − 7, 4 − 8)

= (−2, −4, −4)

a1 = −2, b1 = −4, c1 = −4

Direction ratio of CD = (1 − (−1), 2 − (−2), 5 − 1)

= (2, 4, 4)

a2 = 2, b2 = 4, c2 = 4

`a_1/a_2 = (-2)/2 = -1`

`b_1/b_2 = (-4)/4 = -1`

`c_1/c_2 = (-4)/4 = -1`

Hence, `a_1/a_2 = b_1/b_2 = c_1/c_2`

Lines AB and CD are parallel.

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अध्याय 11: Three Dimensional Geometry - Exercise 11.2 [पृष्ठ ४७७]

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एनसीईआरटी Mathematics Part 1 and 2 [English] Class 12
अध्याय 11 Three Dimensional Geometry
Exercise 11.2 | Q 3 | पृष्ठ ४७७

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