Question

Find the value of 't' for which the vectors , i + 2j - 3k and j - tk are perpendicular.​

Answer 1

Answer:

The value of t is ( -2/3 ).

Step-by-step explanation:

Let us consider , a and b are two perpendicular vectors. Hence , the angle between these two vectors is 90°.( θ say )

from the rule of dot product we know that , x . y = xycosФ

[ Ф is the angle between the vectors x and y ]

after dot product we get ,

a . b = abcosθ = abcos90° = ab × 0 = 0

Here , a =  i + 2j - 3k , b = j - tk

∴ a . b = 0

⇒ ( i + 2j - 3k )( j - tk ) = 0

⇒ 2 + 3t = 0

⇒ t = ( -2/3 )