Finding scalar s for orthogonal vectors with unit vectors

[krugertown]

By evaluating their dot product, find the values of the scalar s for which the two vectors
b=$$\hat{x}$$+s$$\hat{y}$$ and c=$$\hat{x}$$-s$$\hat{y}$$
are orthogonal.


I understand that for the two vecotrs to be perpindicular their dot product must be 0. however I am confused how to go about this problem as there are unit vectors.

Any ideas are appreciated. thanks!

 

[lanedance]

gday krugertown

take the dot product & show me what you get...

the unit vectors are generally orthonormal - meaning orthogonal & unit magnitude, this should help...

 

[krugertown]

so something like $$\hat{x}$$-s$$^{2}$$$$\hat{y}$$?

 

[lanedance]

the results of a dot product should be a scalar not a vector quantity

try writing out the whole dot product