Question

If \[\alpha\], \[\beta\], and \[\gamma\] are the direction angles of a line, which ordered triple gives its direction cosines?

विकल्प

• \[(l,m,n)=(\sin\alpha,\sin\beta,\sin\gamma)\]

• \[(l,m,n)=(\cos\alpha,\cos\beta,\cos\gamma)\]

• \[(l,m,n)=(\alpha,\beta,\gamma)\]

• \[(l,m,n)=(\tan\alpha,\tan\beta,\tan\gamma)\]

Answer 1

The cosines of the direction angles are called direction cosines. Therefore, \[l=\cos\alpha\], \[m=\cos\beta\], and \[n=\cos\gamma\].