AP EAMCET202422 May 2024Evening ShiftMathematicsParabolaActual
Equation of the line touching both parabolas y^2=4 x and x^2=-32 y is
Options
- Ax+2 y+4=0
- B2 x+y-4=0
- Cx-2 y-4=0
- Dx-2 y+4=0
Correct answer
D. x-2 y+4=0
Step-by-step solution
y^2=4 x ...(i) Equation of tangent of (i) is, y=m x+ 1 m , ...(ii) Also, x^2=-32 y ...(iii) Equation of tangent of (iii) is y=m x-(-8 m)^2 y=m x+8 m^2 ...(iv) From (ii) and (iv), 1 m =8 m^2 m= 1 2 So, from (ii), y= x 2 +2 x-2 y+4=0 .