The equations of the tangents drawn from the origin to the circle x2+y2−2rx−2hy+h2=0 are

The equation of any line through the origin (0, 0) isy = mx ---------(1)If line (i) is tangent to the circle x2+y2−2rx−2hy+h2=0, then the length of perpendicular from center (r, h) on (i) is equal to the radius of the circle, i.e.,|mr−h|m2+1=r2+h2−h2 (mr−h)2=m2+1r2 0⋅m2+(2hr)m+r2−h2=0 m=∞,h2−r22hr Substituting these values in (i), we get the tangents as x=0 and h2−r2x−2rhy=0