Consider the expression, y=sinx Differentiate above w.r.t x
dy
dx
=cosx If tangent to y=sinx meet at (h,k) then, (
dy
dx
)(h,k)=cosh The equation of tangent is given by, cosh(x−h)=y−k As tangent is passing through origin so, hcosh=k The given curve is passing through (h,k) so, k=sinh cosh=√1−k2 cos2h=1−k2 h2−k2=h2k2 h2−k2=h2k2 x2−y2=x2y2