Saved Bookmarks
| 1. |
If a chord, which is not a tangent, of the parabola `y^(2)=16x` has the equation 2x+y=p, and midpoint (h,k), then which of the following is (are) possible value(s) of p,h and k ?A. p=5, h=4, k=-3B. p=-1, h=1, k=-3C. p=-2, h=2, k=-4D. p=2, h=3, k=-4 |
|
Answer» Correct Answer - D 4 Parabola, `y^(2)=16x` Equation of chord, 2x+y=p (1) Equation of chord having mid point (h,k) is `T=S_(1)` `ky=8(x+h)=k^(2)-16h` `orky-8x=k^(2)=8h` comparing (1) and (2), we get `(k)/(1)=(-8)/(2)=(k^(2)-8h)/(p)` `rArrk=-4andk^(2)-8h=-4p` From this, we get 16-8h=-4p Clearly, h=3 and p=2. |
|