The curve for which the ratio of the length of the segment by any tangent on the Y−axis to the length of the radius vector is constant (K), is
হানি নাটস
Slope of tangent at
p(x,y)= on y=f(x)dxdyp(x,y)
Equation of tangent at P
⇒x−xy−y=dxdy⇒y−y=dxdy(x−x)
for y-intercept put x=0,
γ=y−xdxdy - (1)
Radius vector OP=x2+y2————-(2)
Given, x2+y2y−xdxdy=k
⇒⇒⇒⇒⇒x2+y2y−xdxdy=k(x2+y2)[ Let y=vx⇒dxdy=v+]vx−x[v+xdxdv]=kx1+v2−xdxdv=k1+v2⇒∫1+v2dv=−k∫xdxln(v+1+v2)=−klnx+lncv+1+v2=xkc
substituting v=y/x
⇒xy+1+(xy)2=xkc⇒xy+x2+y2=xkck−1⇒(y+x2+y2)xk−1=c
∴ Hence, Option ( B ) is the correct answer.