If a = i + j +t k , b = i +2 j +3 k , then the values of ' t ' for which (a+b) and (a-b) are perpendicular, are

Step-by-step solution

We have, aligned a + b & =( i + j +t k )+( i +2 j +3 k ) & =2 i +3 j +(t+3) k aligned and aligned a - b & =( i + j +t k )-( i +2 j +3 k ) & =- j +(t-3) k aligned Since, ( a + b ) and ( a - b ) are perpendicular to each other, then ( a + b ) ( a - b )=0 array cc & [2 i +3 j +(t+3) k ] [- j +(t-3) k ]=0 & 0-3+t^2-9=0 & 0 array t^2=12 t= 2 3