MHT CET20244 May 2024Evening ShiftMathematicsStraight LinesActual
The incenter of the triangle ABC , whose vertices are A (0,2,1), B (-2,0,0) and C (-2,0,2) is
Options
- A( 3 2 ,- 1 2 ,-1 )
- B( 3 2 , 1 2 , 1 )
- C(- 3 2 , 1 2 , 1 )
- D(- 3 2 ,- 1 2 ,-1 )
Correct answer
C. (- 3 2 , 1 2 , 1 )
Step-by-step solution
aligned & Let a =2 j + k , ~b =-2 i , c =-2 i +2 k & AB =-2 i -2 j - k , & BC =2 k & AC =-2 i -2 j + k & | AB |=3,| BC |=2,| AC |=3 aligned Incentre of A B C is given by | AB | c +| BC | a +| AC | b | AB |+| BC |+| AC | aligned & = 3(-2 i +2 k )+2(2 j + k )+3(-2 i ) 3+2+3 & = -12 i +4 j +8 k 8 & =- 3 2 i + 1 2 j + k aligned