हिंदी

Show that the points A, B and C with position vectors a→=3i^-4j^-4k^, b→=2i^-j^+k^ and c→=i^-3j^-5k^, respectively form the vertices of a right angled triangle.

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प्रश्न

Show that the points A, B and C with position vectors `veca = 3hati - 4hatj - 4hatk`, `vecb = 2hati - hatj + hatk` and `vecc = hati - 3hatj - 5hatk`, respectively form the vertices of a right angled triangle.

योग
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उत्तर

Here, `vec(AB) = vecb - veca`

`= (2hati - hatj + hatk) - (3hati - 4hatj - 4hatk)`

`= -hati + 3hatj + 5hatk`

`vec (BC) = vecc - vecb = (hati - 3hatj - 5hatk) - (2hati + hatj + hatk)`

`= hati - 2hatj - 6hatk`

`vec(CA) = veca - vecc = (3hati - 4hatj - 4hatk) - (hati - 3hatj - 5hatk)`

`= 2hati - hatj + hatk`

`|vec(AB)|^2 = (-1)^2 + 3^2 + 5^2`

= 1 + 9 + 25

= 35

`|vec(BC)|^2 = (-1)^2 + (-2)^2 + (-6)^2`

= 1 + 4 + 36

= 41

and `|vec(CA)|^2 = 2^2 + (-1)^2 + 1^2`

= 4 + 1 + 1

= 6

So, `|vec(BC)|^2 = |vec(AB)|^2 + |vec(CA)|^2`

Hence, the triangle is a right angles triangle.

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  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 10: Vector Algebra - Exercise 10.2 [पृष्ठ ४४१]

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एनसीईआरटी Mathematics Part 1 and 2 [English] Class 12
अध्याय 10 Vector Algebra
Exercise 10.2 | Q 17. | पृष्ठ ४४१

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