99 Percentile Qs Bank for JEE MainMathematicsParabola
The focal distance of a point on the parabola y²=16 x whose ordinate is twice the abscissa, is
Options
- A6
- B8
- C10
- D12
Correct answer
B. 8
Step-by-step solution
Given curve is y²=16 x . Let the point be (h, k) . But 2 h=k , then k²=16 h aligned & & 4 h² &=16 h & & h &=0, h=4 & & k &=0, k=8 aligned Points are (0,0),(4,8) . Hence, focal distance are respectively 0+4=4,4+4=8 ( focal distance =h-a)