AP EAMCET2015MathematicsEllipse
The radius of the circle passing through the foci of the ellipse x^2 16 + y^2 9 =1 and having its centre at (0,3) is
Options
- A6
- B4
- C3
- D2
Correct answer
B. 4
Step-by-step solution
Equation of ellipse, x^2 16 + y^2 9 =1a^2=16 a=4, b^2=9 b=3 Here, a>b Now, e= 1- b^2 a^2 = 1- 9 16 = 7 4 Focus =( a e, 0)= 7 , 0 Since, the circle passes through P ( 7 , 0) and centre at C (0,3) . aligned & Radius =r c p= (0-7)^2+(3-0)^2 & = 7+9 = 16 =4 aligned