"If vector ` vec b=(t a nalpha,-1, 2sqrt(sinalpha//2))a n d vec c=(t a nalpha, t a nalpha,
Channel: Doubtnut
Date: 28/06/2020

"If vector ` vec b=(t a nalpha,-1, 2sqrt(sinalpha//2))a n d vec c=(t a nalpha, t a nalpha, 3/(sqrt(sinalpha//2)))`
 are orthogonal and vector ` vec a=(1,3,sin2alpha)`
 makes an obtuse angle with
  the z-axis, then the value of `alpha`
 is
 `alpha=(4n+1)pi+tan^(-1)2`
 b. `alpha=(4n+1)pi-tan^(-1)2`
 
 c. `alpha=(4n+2)pi+tan^(-1)2`
 d. `alpha=(4n+2)pi-tan^(-1)2`"