Equation of common tangent to y2=8x and x2+y2=2 is

Equation of tangent to y2=8x is y=mx+2m⇒m2x−my+2=0 is also tangent to x2+y2=2⇒|2|m4+m2=2⇒m4+m2−2=0⇒m2+2m2−1=0⇒m=±1∴ required equation y=(±1)x+2(±1)⇒y=±(x+2)