MathematicsMedium249×since 2002Q2450If the line of intersection of the planes ax+by=3a x+b y=3ax+by=3 and ax+by+cz=0a x+b y+c z=0ax+by+cz=0, a >0>0>0 makes an angle 30∘30^{\circ}30∘ with the plane y−z+2=0y-z+2=0y−z+2=0, then the direction cosines of the line are :A12,12,0\frac{1}{\sqrt{2}}, \frac{1}{\sqrt{2}}, 021,21,0B12,± 12,0\frac{1}{\sqrt{2}}, \pm \,\frac{1}{\sqrt{2}}, 021,±21,0C15,−25,0\frac{1}{\sqrt{5}},-\frac{2}{\sqrt{5}}, 051,−52,0D12,−32,0\frac{1}{2},-\frac{\sqrt{3}}{2}, 021,−23,0Check answerSkip