Question

Find a value for y such that the vectors 15i - 3j and -4i + yj are perpendicular.

Answer 1

What do you know about the relation between "dot product" of vectors and perpendicularity ?

Answer 2

@ganeshie8 No, I'm not sure on the relation between dot product vectors and perpendicularity. I know how to find the dot product though.

Answer 3

Ahh okay, try using below relation :

if the vectors are perpendicular, then the dot product of those vectors is "zero"

Answer 4

@ganeshie8 So my two vectors would be <15, -3> and <-4, y>. Then set the dot product equal to 0 and solve for y. I got -20

Answer 5

Looks good!