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If `vecA = 2hati + hatj -3hatk, vecB = hati- 2hatj + hatk` and `vecC = - hati + hatj - 4hatk`, Calculate (i) `vecA.(vecB xx vecC), (ii)vecC (vecAxx vecB), (iii) vecA xx (vecB xx vecC)` |
Answer» Correct Answer - (i) 20, (ii) 20,(iii)(`8hati -19hatj+ 3 hatk`) (i) `vecA.(vecBxx vecC) = vecA.[(8-1) hati - (-4 + 1) hatj + (1-2) hatk]` `" "= (2hati + hatj - 3hatk) .(7hati + 3hatj - hatk)=20` (ii) `vecC.(vecA xx vecB) = vecC.[(6-1)hati - (2+3)hatj +(-4-1)hatk]` `" "(-hati + hatj - 4hatk).(5hati -5hatj- 5hatk)= 20` (iii) `vecA xx (vecB xx vecC) = (vecA. vecC) vecB - (vecA. vecB).vecC` `(11) vecB- (3)vecC = (22 hati - 22hatj+ 11hatk)-(3hati - 3hatj- 12hatk)` `=8hati- 19hati -hatk` |
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