The line x−23=y−12=z−1−1 intersects the curve x2−y2=a2 ; z=0 then absolute value of a  is equal to

For the point where the line intersects the curve, we have z = 0 So, x−23=y−12=0−1−1⇒x=5   and  y=3 Putting these values in x2−y2=a2,  we get a2=16 i.e., a=±4