मराठी

Let a→=i^+j^,b→=i^-j^ and c→=i^+j^+k^. If n^ is a unit vector such that a→.n^ = 0 and b→.n^ = 0, then find |c→.n^|. - Mathematics

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प्रश्न

Let `veca = hati + hatj, vecb = hati - hatj` and `vecc = hati + hatj + hatk`. If `hatn` is a unit vector such that `veca.hatn` = 0 and `vecb.hatn` = 0, then find `|vecc.hatn|`.

बेरीज
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उत्तर

Given, `veca = hati + hatj, vecb = hati - hatj`

and `vecc = hati + hatj + hatk`

Also, given `veca.hatn` = 0

and `vecb.hatn` = 0

Here, `hatn = (veca xx vecb)/(|veca xx vecb|)`

Here, `veca xx vecb = |(hati, hatj, hatk),(1, 1, 0),(1, -1, 0)|`

= `hati(0 - 0) - hatj(0 - 0) + hatk(-1 - 1)`

= `-2hatk`

∴ `hatn = (-2hatk)/sqrt((-2)^2) = - hatk`

Therefore, `|vecc.hatn| = |(hati + hatj + hatk).(-hatk)|`

= |–1|

= 1

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2021-2022 (March) Term 2 - Delhi Set 2

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