# If two vectors whose direction ratios are 1,2,3 and -k,2,1 are perpendicular to each other then, a) k=7 b) k=4 c) k=3 O d) k=6 me especially since we had be 1 poir 82) I don't know why he turned friends for so long.​

(a)k=7

Step-by-step explanation:

We are given that

Two vectors whose direction ratios are 1,2,3 and -k,2,1.

Let

We have to find the value of k.

We are given that two vectors are perpendicular to each other.

We know that two vectors are perpendicular to each other then

Substitute the values

Hence, option a is correct.

your answer is d 2,500

step-by-step explanation: