For `alpha=pi//` which of the following hold (s) good?

For alpha=pi/7 which of the following hold (s) good?

For alpha=pi/7 which of the following hold(s) good? (a) tanalphatan2alphatan3alpha=tan3alpha-tan2alpha-tanalpha (b)cos e calpha=cos e c2alpha+cos e c4alpha (c)cosalpha-cos2alpha+cos3alpha=1/2 (d)8cosalphacos2alphacos4alpha=1

If vec A,vec B,vec C and vec D are four non zero vectors in the same plane no two of which are collinear then which of the following hold (s) good?

Let alpha,betaa n dgamma be some angles in the first quadrant satisfying tan(alpha+beta)=(15)/8a n dcos e cgamma=(17)/8, then which of the following hold(s) good? (a) alpha+beta+gamma=pi (b)cotalpha+tanbeta+tangamma=tanalphatanbetatangamma (c)tanalpha+tanbeta+tangamma=tanalphatanbetatangamma (d)tanalphatanbeta+tanbetatangamma+tangammatanalpha=1

The locus of the point of intersection of those normals to the parabola x^(2)=8y which are at right angles to each other,is a parabola. Which of the following hold (s) good in respect of the loucus?

If b+c+,c+a,a+b are in H.P. then which of the following hold(s) good ?