9. Incident ray is along the unit vector v and the reflected ray is along the unit vector w . The normal is along unit vector a outwards. Express vector $w$ in terms of vector $a$ and $v$.
The locus of the centre of a circle which touches the $x$-axis and also externally touches the circle $x ^ { 2 } + ( y - 1 ) ^ { 2 } = 1$ is
9. Incident ray is along the unit vector v and the reflected ray is along the unit vector w . The normal is along unit vector a outwards. Express vector $w$ in terms of vector $a$ and $v$.\\