Question

# If vectors A=coswti+sinwtj B= cos wt/2 i+sinwt/j are functions of time then the value of t at which they are orthogonal to each other is

Solution

orthogonal is perpendicular

so A.B=0

=cosut cos wt/2+sin wt/2sinwt=0

= cos(wt-wt/2)=0

=cos(wt/2)=0 = wt/2=π/2

=t=π/w