JEE Main2008MathematicsDifferential EquationsActual
The differential equation of the family of circles with fixed radius 5 units and centre on the line y=2 is
Options
- A(x-2) y^ 2 =25-(y-2)^2
- B(y-2) y^ 2 =25-(y-2)^2
- C(y-2)^2 y^ 2 =25-(y-2)^2
- D(x-2)^2 y^ 2 =25-(y-2)^2
Correct answer
C. (y-2)^2 y^ 2 =25-(y-2)^2
Step-by-step solution
aligned & (x-h)^2+(y-2)^2=25 & 2(x-h)+2(y-2) d y d x =0 & (x-h)=-(y-2) d y d x aligned substituting in (1), we have aligned & (y-2)^2 ( d y d x )^2+(y-2)^2=25 & (y-2)^2 y^ 2 =25-(y-2)^2 aligned