If the three vectors are coplanar, then find `x`. `A=hati-2hatj+3hatk, – InterviewSolution

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1.	If the three vectors are coplanar, then find `x`. `A=hati-2hatj+3hatk, B=xhatj+3hatk, C=7hati+3hatj-11hatk`A. `36//21`B. `-51//32`C. `51//32`D. `-36//21`
Answer» (b) The three vectors are coplanar, if their scalar tripler product is zero. i.e. `A.(BxxC)=0=\|(1, -2, 3),(0, x, 3),(7, 3, -11)\|=0` `(1)[-x(11)-9=+2(0-21)+3(0-7x)=0` `-11x-9-42-21x=0implies-32x-51=0impliesx=- 51/32`

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