AP EAMCET202023 Sep 2020Morning ShiftMathematicsEllipseActual
If the line y = 2 x + c touches the curve x 2 + 4 y 2 = 4 , then c 2 =
Options
- A65
- B17
- C63
- D8
Correct answer
B. 17
Step-by-step solution
y = 2 x + c is tangent to ellipse x 2 4 + y 2 1 = 1 Tangent : y = m x ± 4 m 2 + 1 On comparing m = 2 ,   c 2 = 4 m 2 + 1 ⇒ c 2 = 17