InterviewSolution
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InterviewSolution
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The ratio in which the line segment joining the points whose position vectors are `2hati-4hatj-7hatkand-3hati+5hatj-8hatk` is divided by the plane whose equationis `hatr.(hati-2hatj+3hatk)=13`isA. 13:12 internallyB. 12:25 externallyC. 13:25 internallyD. 37:25 internally |
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Answer» Correct Answer - b Let P be the point and it divides the line segment in the ratio `lamda :1 `. Then, `" "vec(OP)=vecr= (-3lamda+2)/(lamda+1)hati+ (5lamda-4)/(lamda+1)hatj+ (-8lamda-7)/(lamda+1)hatk` It satisfies `vecr*(hati-2hatj+3hatk)= 13`. So, `" "(-3lamda+2)/(lamda+1)-2(5lamda-4)/(lamda+1)+3(-8lamda-7)/(lamda+1)=13` or `" "-3lamda+2-2(5lamda-4)+3(-8lamda-7)= 13 (lamda+1)` or `" "-37lamda-11=13lamda+13 or 50 lamda= -24 or lamda= - (12)/(25)` |
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